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aka: CSI Crime Scene Investigation

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The "classic" cast.

"Concentrate on what cannot lie — the evidence."
Gil Grissom
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CSI (full title CSI: Crime Scene Investigation and upon revival, CSI: Vegas)note  is a highly successful TV show (2000-2015) about a group of graveyard-shift crime scene investigators in Las Vegas led originally by enigmatic scientist Gil Grissom, then, following his departure, by ex-stripper and single mother Catherine Willows, and finally, by quirky scientist DB Russell.

Initially touted as a show where the evidence was the main character and the actual characters were little more than flat stereotypes with "quirks" added almost as an afterthought, the series progressed over its thirteen seasons to make the characters a little more rounded and include more of their personal lives and histories in the story lines. It also moved on from a fairly straightforward forensics approach to more high-tech approaches that aren't necessarily possible in real life, requiring some degree of suspension of disbelief from the viewer. CSI runs into the Road of Trials (Part of Hero's Journey) many times throughout the series. CSI as a forensic/mystery show continued for many years, holding on very strongly and getting more interesting with time.

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The series influenced a great many subsequent programs, particularly from the early 2000s to the early 2010s, where police procedurals involving large casts of characters, often focused around a specific type of crime/evidence/investigation methods, were for a while a large mainstay of TV programming. Most directly, it inspired its producer, Jerry Bruckheimer, to try and replicate this success with Without a Trace and Cold Case (both in the same verse). It also followed in Law & Order's "franchise" footsteps, with CSI: Miami (Yeeeeeeeaaaahh!), CSI: NY and CSI: Cyber. There are 797 total episodes of CSI, CSI: Miami, CSI: NY, and CSI: Cyber, not including books, comic books, and video games related to the franchise. Please note, however, that it is not the oldest of the current crop of forensic shows, a title held by British show Silent Witness.

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Gil Grissom's frequent one-liners right before the opening credits or an ad break are a well known example of a Quip to Black, although Horatio Caine's versions are perhaps the best known - mostly due to the heaping layer of cheese added to them. Pretty much established the Necro Cam, which it uses as a device to re-enact for the viewers every single gruesome detail that can be extracted from a crime scene, and every theory it spawns.

The uncanny effectiveness of the show's Applied Phlebotinum has caused some to suspect that it's not actually set in the present day, but, rather, 20 Minutes into the Future (on-screen dates, though, put it in the Present Day).

The show (and its spinoffs) have given rise to what legal professionals call "The CSI Effect": the necessity of compressing what would normally be months worth of delicate and time-consuming lab work into a 40-minute television episode causes similarly unrealistic expectations in potential real-world jurors. As a result, the uninformed juror will assume that what they see on the show is happening as it actually occurs, as opposed to being fabricated and accelerated for television. It's also sometimes created difficulties in crime-fighting, since the show shining the limelight on forensic techniques (aforementioned Artistic License notwithstanding) has prompted higher-end criminals to take steps to minimize what forensic evidence they leave behind (e.g. wearing gloves to avoid fingerprints).

The show aired a total of 15 seasons before being cancelled in May 2015. A two-hour movie to conclude the show's run aired on September 27, 2015, which brought back original stars William Petersen and Marg Helgenberger.

CBS has announced a 20th anniversary revival run of the series for 2021, which is set to feature various returning cast members as well as a few new ones.


This show provides examples of:

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    A-D 
  • Abnormal Ammo: One episode had bullets made of frozen ground beef.
  • Absentee Actor: William Petersen's absence in a series of episodes brought in Liev Schreiber as Petersen took a break from CSI while he starred in a play called Dublin Carol, a twist on Dickens' A Christmas Carol in Providence, R.I. The episode "Gum Drops" was changed when Petersen left town due to a death in the family. The focuses of the episode changed from Grissom to Nick being certain Cassie was alive. "Genetic Disorder" was changed from a Nick-centric episode to a Greg-centric one when George Eads left town for his father's funeral.
    • On "Gum Drops", given what Nick himself had been through and how he could empathize with her plight, this change was probably an improvement. "Genetic Disorder" becoming Greg-centric can be seen as an improvement as well, as it shows how much Greg has matured as a person and as an investigator over the past decade. He ultimately refuses to jump to conclusions, waits to get official results, and calls other characters out for assuming Doc Robbins is guilty of something (Hodges and Brass). Compare this to a season 1 episode where Greg actually does jump to a conclusion about a couple, and he is found wrong about it.
  • Abusive Parents: Several in the series.
    • In "Turn of the Screws", A jealous and clearly unhinged mother Raina accused her 13-year-old daughter Tessa of trying to steal her younger boyfriend away from her. The mother slut-shames her daughter, calls her names and yells at her for an innocent thing. As the daughter denied this and walked away from their argument, Raina grabbed a shovel and hit Tessa in the back of the head, killing her.
  • Accidental Hero: Witnesses who unknowingly obtain or provide useful evidence have made life infinitely easier for the CSIs on multiple occasions.
  • Accidental Murder: One episode features an accident made to look like a murder. A three-year-old boy accidentally suffocates his infant brother while playing with him, and to prevent the little boy from having to live down this act all his life the parents and their oldest son concoct an elaborate fake kidnapping-murder scheme that manages to fool the CSIs for most of the episode. But the whole thing comes apart when they manage to trace the "ransom note" to the family's own printer.
  • Accident, Not Murder:
    • In "Chaos Theory", the crew investigate a missing coed who eventually turns up dead. Although they uncover several other crimes along the way, the girl's death is actually an accident caused by a confluence of unlikely events.
    • "Crate 'N Burial" involves the investigation of a woman found dead in a boat. It later comes out that she died by accident. But when they go to tell her husband this, they find that he's already murdered her lover, believing him responsible for her murder.
    • Two episodes, "Gentle, Gentle" and "The Chick Chop Flick Shop," both feature the offbeat twist of accidents deliberately made to look like murders, the motive in both cases being to send the authorities on a wild goose chase for a nonexistent killer so they don't discover some even more disturbing fact about why the accident occurred. In the former, a three-year-old boy accidentally smothers his one-year-old brother while playing with him, and the parents stage the scene in an attempt to avoid the incident following their son the entire life, while in the latter the accident exposes the fact that the building in which it occurred was guilty of numerous safety code violations, and the fake murder was an attempt to save the jobs of the people working there.
    • "A La Cart" opens with a decapitated head bouncing down a country road before finally coming to rest in the hands of crew picking up trash on the side of the road. The CSIs soon discover the headless body dumped on the side of the road. However, what appears to have been a brutal murder turns out to have been a bizarre accident involving a go-kart and blown truck tire.
    • One of the deaths in "The Descent of Man", a New Age holy man found dead of head trauma in the desert, was the victim of an eagle mistaking his bald head for a rock, and dropped a tortoise on him while he was meditating. Langston only found out by accident when he recited the story of Aeschylus to the team.
  • Adaptational Heroism: Unlike White Sqweegel in the Level 26: Dark Origins novel, Black Sqweegel here is a Well-Intentioned Extremist targeting Asshole Victims with dark secrets. He seemingly has a code of conduct and honor as well, even sparing a child who witnesses one of his murders in a car wash.
  • Adult Fear: One episode had two boys who went missing and the main suspect is a pedophile. It didn't help when the team had to enlist his help to try to find the boys and he began to describe in detail to Grissom how he would lure a child to him by gaining their trust. Another suspect was one of the boys' abusive grandfather. Imagine you were the son of that man, forced to leave your son with him because the grandfather was the only one available to look after your son. And failed. The pedophile did it.
  • Affably Evil: Doctor Dave, the serial-killing dentist from the episode "Sweet Jane". He has a pleasant chat with Catherine about loving his work (dentistry, not serial killing), and how he especially takes care to make a child's first trip to the dentist the least frightening and painful as possible. And when she confronts him about his crimes, not only does he never once deny that he is, in fact, a murderer, he describes the killings in the same affectionate tone that he just described trying to make a trip to the dentist less scary for kids. Ned Beatty's note-perfect performance was a complete blend of utterly friendly and utterly scary-creepy. That being said, he does act like a Jerkass when interacting with the authorities once he's caught.
  • Affectionate Parody: In one episode, to Darker and Edgier reimaginings of classic sci-fi shows. Hodges' dream sequences during the episode (where he sees himself as The Captain of the Star Trek: The Original Series Expy) are pretty much a love letter to Trek (taking details mostly from the episodes "The Gamesters of Triskelion" and "The Cage" - and getting away with all of the borrowing mostly because Trek and CSI are both Paramount franchises). Fittingly enough, the episode's writers also worked on Star Trek: Deep Space Nine.
  • Air-Vent Passageway: In "Karma to Burn", when Finn and D.B.'s granddaughter Katie are kidnapped, Finn is able to prise open a vent cover to allow Katie to crawl out (her being small enough to fit in the vent). However, she is immediately recaptured.
  • Alien Autopsy: Subverted in "Viva Las Vegas", when the "alien" was identified as a costumed human with a medical condition that made him look a bit like a Grey.
  • All Bikers Are Hells Angels: In "Hog Heaven", the team must find out who tipped a biker gang off after an undercover cop in their midst is murdered.
  • All Girls Want Bad Boys: Nate Haskel despite the numerous women he's killed and raped has fairly large group of women obsessed with him, even he acknowledges that he's a chick magnet making him an in-universe Draco in Leather Pants. His harem even go so far as to break him out of prison after he stabs Langston and is found guilty for all his past murders.
  • All Psychology Is Freudian:
    • Episode "4x4"
      Greg Sanders: No matter how hard you work to get big, there's always someone bigger.
      Sara Sidle: It could be what keeps them going. Like Freud said, "Anatomy is destiny".
      Greg Sanders: What do you think Freud would have to say about one of these being the murder weapon?
    • Episode "Fur And Loathing"
      Grissom: Well, Freud said that the only unusual sexual behavior was to have none at all.
    • Episode "Lab Rats"
      Hodges: Freud's theory on the uncanny raises the point that as children we want the doll to come to life. But as adults, we are terrified by the idea. The doll could represent the uncanny that is feared. The Sandman."
    • Episode "King Baby" had a victim with an infantilism fetish (a fetish for pretending to be a baby and being nursed). At the end of the episode we meet the victim's mother, who mentions she never breastfed her son, believing it would make her soft.
  • Aluminum Christmas Trees: Some of the fetishes featured in the plots of some episodes seem so out there many viewers just assume they were something made up for the show. in fact, most if not all of them are completely real.
  • Ambiguous Disorder: Gil Grissom is all sorts of quirky and odd, a bit too literal, not exactly social, but not exactly unsocial either, kinda fumbling...how much so, it just depends on what the script calls for.
  • Amusement Park of Doom: When Catherine is assigned to investigate the death of a six-year old girl named Sandy Dantini during a tunnel ride with her mother at a carnival in the Season One episode, Justice is Served, the death of the girl is built up to be because of this trope. The manager is a registered sex offender who is now running place designed especially for small children, and happened to be seen near the ride during the time of the murder (which happened to be the only ride in the carnival that went into the dark). After finding a hammer in said ride, the investigators posit that Pickens either abducted Sandy from the ride and killed her with the hammer because there was no way for him to escape unnoticed with her, or that Sandy was killed by Pickett's non-code conforming ride and tried to repair it to cover the evidence. It turns out that the real murderer was Sandy's own mother, as parenthood was getting in the way of her relationship with her boyfriend, and intentionally killed Sandy at a carnival as several of them fit this trope to a perfect T, and knew that the authorities would immediately suspect the carnival staff or the shoddy ride itself as the cause of Sandy's death rather than her.
  • And Starring: Paul Guilfoyle gets an "And", Robert David Hall a "With". Laurence Fishburne - because he is, well, Laurence Fishburne - goes first in the order. Ditto with Ted Danson.
  • Antagonistic Offspring: Ellie Brass, in all of her appearances.
    • Especially in the season 14 premiere, "The Devil and D.B. Russell," where it turns out she's the mastermind behind the killings who also offs her mother.
  • An Arm and a Leg: In "Disarmed & Dangerous", the Victim of the Week is beaten to death by an attacker who is in such a steroid-fulled rage that he literally rips the victim's arm off.
  • Artistic License:
    • While hiding a pistol inside a computer case could cause issues with cooling - either due to interfering with airflow, or the fans themselves, it would not prevent a computer from booting up.
    • The pipes in the episode "Who Shot Sherlock?" are repeatedly referred to by several characters as "Meerschaums". They're calabashes.
  • Artistic License – Biology: The series plays fast and loose with various aspects of biology, particularly on the subject of fingerprints, which aren't necessarily left as easily or on as many surfaces as the show would have one believe.
    • One CGI montage in "Grave Danger" shows fire ants injecting venom through their bites. Real ants only bite to get hold and then inject venom through their abdomen stings, like bees and wasps.
  • Artistic License – Chemistry: The "yiffing party" of the CSI episode "Fur And Loathing" is indeed pure fiction. Mainly due to the fact that having sex while wearing a fur suit can lead to massive heat exhaustion.
  • Artistic License – Physics: In the Episode "Overload", a man is electrocuted because somebody drove a nail through his rubber soles, circumventing the insulation. So far, so good - but then Grissom explains that you are safe from lightning in your car, because tyres are made from insulating rubber.
  • Ascended Extra: Nate Haskell, the Dick and Jane Killer.
  • As Himself: Former Las Vegas mayor Oscar Goodman plays himself in two episodes. In the second, "Maid Man", he is the victim of an assassination attempt.
  • A-Team Montage: As the various forensic specialists build a case.
  • Autopsy Snack Time: Given a Take That! when Doc Robbins irately says of a long retired coroner (who missed something in the original autopsy of someone who was to be exhumed) that he "held a scalpel in one hand and a hot dog in the other."
  • Back for the Finale: Grissom, Willows, Brass, Lindsey Willows (now a newbie CSI herself), Lady Heather, and in an especially strange example, former Villain of the Week Leon Sneller/Jacob Wolfowitz, the murderer of Heather's daughter, reappears as a mummified corpse, having himself been killed by Heather's Stalker with a Crush.
  • Bad Guys Play Pool: Very prominent in "Dead Rails", where the CSI team investigates the murder of a pool hustler.
  • Bar Brawl: A bar brawl erupts in a country and western bar in "Bull"; an episode that employs a lot of tropes associated with The Western.
  • Be as Unhelpful as Possible: When a member of CSI intimates that the husband is always the first suspect when a wife is murdered, the husband's response is typically "You think I did this? This interview is over!" - inadvertently doing the pragmatic thing. (But again, Truth in Television; police expect ordinary people to get angry when accused of crimes they didn't commit.)
  • Beastly Bloodsports: "Lying Down With Dogs", where a wealthy humanitarian was found dead and then found to be involved in dogfighting.
  • Beeping Computers: Not so much used as abused.
  • Being Good Sucks: Oftentimes, during the course of an investigation, someone's life will be ruined, as Leo Finley can attest. Though the best example of this is "Say Uncle", where Grissom eventually learns that an eight-year-old boy, driven over the Despair Event Horizon when his drug addict mother shot his uncle to death, took the uncle's gun and shot his mother to death. The episode ends with the boy going off to juvie, and Grissom expressing regret over the whole situation.
  • Berserk Button: In addition to this trope being the motive for crime, Grissom himself states that he absolutely can't stand spouse abusers, drug dealers, and people who hurt children.
    • On a wider scale, each investigator has their own. Catherine can't handle cases that even tangentially involve kids without going nuts, Sara can't deal with spousal abusers, etc....
  • The Bet: In "Hitting for the Cycle", various people bet on which team member will be first to catch a "natural" death, completing the full Cycle of four potential causes (homicide, suicide, accidental, natural). Doc Robbins wins the pot, having sensibly bet on his own assistant David, who examines every corpse.
  • Better to Die than Be Killed: Several notable killers choose this way out - Paul Millander and Kevin Greer simply kill themselves, while Nate Haskell goads Langston into doing it for him.
  • Beware the Nice Ones: D.B. is usually a pretty nice, easygoing, sometimes funny guy. But threaten his family or his CSIs and you will definitely regret it.
  • Big Blackout: "CSI Unplugged". Henry and Hodges get trapped in an elevator, so the rest of the team have to deal with a complicated kidnapping case without them for most of the episode.
  • Big Eater: Deconstructed in an episode where the team investigates an obese man that apparently ate himself to death. What looks like a silly comedic episode at first gets a really sad ending when it is revealed that the victim was a mentally ill person with Prader-Willi Syndrome, a genetic disorder that causes insatiable hunger among other symptoms, and that he had been let loose by an unfit caretaker who wanted to use him to win an eating contest.
  • Big Sister Instinct: Both Sara and Catherine seem to regard Greg (who is the youngest of the group) like a little brother. In particular, they are the most upset when Greg is almost beaten to death in "Fannysmacking"
  • Bilingual Bonus: Probably unintentional, there's an episode where a fat man is killed and he has the surname Brenner which means 'burning' in Norwegian, in the same episode there was a murder fire.
  • Bitter Almonds: Subverted: a big show is made of only 20% of people being able to smell cyanide, and there is another, more useful, symptom. So many forensic miracles on this show, and yet this trick doesn't work!
  • Bitter Sweet Ending: When the series was cancelled in May 2015 Big Baddies of the season the Gig Harbor Killer(s) were killed but Finn is left in a coma.
  • Black Blood / Alien Blood: In Season Eight's "The Theory of Everything", a number of dead people wound up with avocado-green blood.
  • Black Bra and Panties: In the montage that opens "Viva Las Vegas", a woman appears in black bra and panties. She later becomes a Victim of the Week in a The Murder After scenario, still clad in the black bra and panties.
  • Black Comedy: Pretty much a given in a show about police officers and CSIs dealing with death on a daily basis.
  • Blaming the Victim: "Turning of the Screws" Catherine is looking into the murder of a young girl. She initially suspects the mother's handyman boyfriend, especially after blood is found on a shovel in his truck. However, fingerprints on the shovel reveal it was the mother who killed the girl. The mother then claimed that the girl was trying to come on to the boyfriend. She became convinced of this when the boyfriend gave the girl a lift home from school (which was entirely innocent). Catherine points out that the girl was all of thirteen.
  • Blast Out: "Better Off Dead" opens with a furious firefight in a gun store that results in multiple fatalities. Flashbacks later show that is was triggered by a Blast Out, and the man responsible walked away without a scratch despite standing at the centre of the hail of bullets.
  • Blonde, Brunette, Redhead: Brody, Sara, and Catherine within the show until Catherine left; among the female leads across the spinoffs there's blonde Calleigh and brunettes Stella and Danville.
  • Blood Is the New Black: "Bad to the Bone", a particularly nasty murderer is caught almost immediately when he casually walks into a diner to wash his hands after beating a man to death.
  • A Bloody Mess: In "Alter Boys", a suspected blood stain turns out to be red sauce.
  • Body in a Breadbox: Every two or three episodes, a corpse turns up someplace really odd.
  • Body Paint: In "All for Our Country", Catherine and Sara investigate what happened to a college football fan whose body is found bloated in the bath tub. Sara examines a shirt and finds the number 7 traced on the inside. Catherine says it comes from the man's chest where it was printed in makeup.
  • Bodybag Trick: Catherine and D.B. use this trick to get themselves smuggled back into the lab when a hit team is looking for them in "Willows in the Wind".
  • Bookmark Clue: In "Nesting Dolls", Warrick finds a dictionary with certain romantic words highlighted. A set of camera booth photos featuring Victim of the Week Svetlana and a guy is being used as a bookmark. Catherine tells Warrick that the guy in the pictures is not Svetlana's husband Andrew.
  • Book Safe: In "Skin in the Game", the Theme Serial Killer leaves hollowed out Bibles containing dowels at the scene of his crimes.
  • Born from a Dead Woman: Doc Robbins once realized that a teenage girl who'd hanged herself just minutes before he and Nick arrived on-scene still had a living fetus inside her, so he hastily performed a C-section and was able to save the baby.
  • Born Lucky: For one single day, David Hodges was the luckiest guy on earth. His lucky day even allowed Grissom to gain important insight on the Miniature Killer case.
  • The Boxing Episode: "Fight Night" finds Grissom learning the ins and outs of the sport while investigating the death of a boxer who had twice previously beaten his opponent of the night.
  • Bookends: The episode "Kiss Kiss, Bye Bye" opens with a black and white shot of the Vegas Vic sign which slowly gains color, with Frank Sinatra blasting loudly. The ending fades back into black and white, the last shot of the same sign and another Sinatra ballad plays.
  • Bowling for Ratings: In "Lover's Lanes", a decapitated head comes up the ball return during a bowling tournament. At the end of the episode, the entire team goes out bowling.
  • Boys Like Creepy Critters: Grissom mentions he was like this in school (naturally), but his first crush was an inversion ("She liked bugs too.").
  • Brains and Bondage: Grissom's one-time potential love interest Lady Heather was an intelligent woman who ran an S&M club.
  • Brain Bleach: Common throughout various characters, be it core cast or those involved in the cases. Nick and Ray seems to want some when they find out just exactly WHAT those vacuum-packed panties were after seeing one show attendee demonstrate in Season Ten's "The Panty Sniffer".
    • Definitely a few people's reaction to the episode "Blood Drops". Anyone who has seen the episode knows why, anyone who hasn't should consider themselves lucky.
  • Breather Episode: Several, usually with the death turning out to be accidental.
  • Bring My Brown Pants:
    • The guy who had a heart attack when he thought he was being pushed out of a helicopter thousands of feet off the ground with no chute. He was only a few feet up but had a heart attack. Beforehand, he’s shown to have wet himself.
    • Also the witness in “Paper or Plastic”. He is nervous as he talks to Catherine and when asked if he had somewhere he needed to be, he said he had to go change his pants.
  • Broken Bird: Sara Sidle has a pretty serious case of this.
  • Broken Pedestal: Catherine's mentor.
  • Bullet Time: Commendably, they waited until Morpheus had thoroughly settled in before showing a bullet-time extravaganza (complete with The Men in Black!).
  • Bungled Suicide: In "Better Off Dead", the team investigates what appears to be a one-man crime wave across Las Vegas that has left three people (and a dog) dead, and another wounded. It turns out have started with a bungled suicide, with all of the chaos that followed being the result of the suicidal man's attempt to put things right (and kill himself — and being completely unable to, much to his despair).
  • Bunny-Ears Lawyer: At least half the cast are deeply messed up despite being good at their jobs. Although downplayed in later seasons, early episodes often emphasized that this was the LVPD crime lab's night crew. Shows with workplace settings often allude to a day shift, who remain off-camera and provide a convenient explanation for mix-ups or miscommunications. On the rare occasion that someone from the day shift appears onscreen, they may well be wearing Bunny Ears — and if a member of the main cast works a day shift, they may be the only one NOT wearing Bunnny Ears. This is often Truth in Television: second (3PM to 11PM) or third (11PM to 6AM) shift hours make a normal social life very difficult and anyone who works that schedule long-term is probably a little bonkers. CSI was an entire series about those third shift oddballs.
    • In a cast full of weirdos, the title definitely goes to Hodges, who starts out so mentally unbalanced that in Real Life he not only would never be allowed to work with law enforcement in any capacity, but probably wouldn't even be allowed outdoors without some kind of supervision. Even in-universe, he's had trouble holding down a job for exactly those reasons.
    • Before Hodges joined the cast, Grissom held the title. It's clear why he hasn't risen further in the department — races cockroaches for fun, avoids paperwork to the detriment of his subordinates — but he's way more than competent at his job.
    • Actually played literally at one point: A lawyer wearing a bunny-mask posed as a ransom-holder for his client.
  • Buried Alive:
    • Nick, after being kidnapped, in "Grave Danger".
    • There’s also a Victim of the Week in the third episode who had this happen, though it was originally a Faked Kidnapping until the guy turned on her.
    • In the season 6 episode "Up in Smoke," the dead body leads to searching for another body that was found sealed into a recently expanded brick chimney wall. Catherine and Sara initially reference Edgar Allan Poe's The Tell-Tale Heart but then describe it as Poe's The Cask of Amontillado when they realize the victim wasn't dead yet when she was being sealed up.
  • The Bus Came Back: First Sara, after leaving for about a season and a half. Grissom and Catherine also returned for the series finale.
  • The Butler Did It: In "Random Acts of Violence", Nick is called to investigate who murdered the supervisor of a high tech company in the sealed computer room, with only three other employees on the floor outside. After thoroughly investigating them, he realizes that the real "murderer" is an AC repairman working in the room directly above the computer room, whom nobody had noticed. He dropped his hammer accidentally, it fell through an air-vent, hit the victim fatally on the head, and was then retrieved by the repairman, who said nothing to keep himself out of trouble.
  • Call-Back:
    • Catherine's final scene includes a reference to the "King Kong on cocaine" line she used to describe the joy of the job to Holly Gribbs, way back in the pilot.
    • Season 15's "The Last Ride" has Sara set off the alarm on a jerk's fancy car to get his attention, the same way she did all the way back in "Last Laugh" in Season 3.
  • Calling the Old Man Out: Catherine, after Lindsey is kidnapped, and a few other times as well.
  • Call It Karma: A low-budget porn director slashes the throat of an actress that had been revealed to be HIV-positive and thus unable to make more porn films. Her blood spills all over his face, some of it getting inside him through the eyes, and he gets AIDS himself as a result.
  • Canon Immigrant: Sqweegel, who originated in Anthony Zuiker's digital novel "Level 26".
  • Can't Get Away with Nuthin': Catherine visits the Highball after work once. Naturally, a murder occurs there, and she gets chewed out by everyone for failing to mention that she went there for a drink until they haul a Smug Snake suspect in and he recognizes her. Her daughter and mother also join in the shunning, and the episode ends with Gil giving her the silent treatment, followed by a curt lecture on how an 'act of omission' makes her just like a common perpetrator.
  • Camera Abuse: In the episode, "Felonius Monk", the camera is shot by a paintball round.
  • Candlelit Bath: In "Who and What", the first Victim of the Week is taking a candlelit bath when the killer enters the bathroom to bludgeon her to death with a hammer.
  • Can't Get in Trouble for Nuthin': In one episode, the Victim Of The Week in the B plot turns out to have been a homeless man. He tried to get sent to jail (for free food and shelter) by punching a police officer. Said officer realized what he was doing and left him handcuffed, apparently failing to realize this would lead to his death.
  • Car Cushion: In "The Happy Place", the Victim of the Week swan dives off her balcony onto the roof of a bus: landing with enough force to shatter the bus windows.
  • Carpet-Rolled Corpse: In "CSI Unplugged", the Body of the Week is rolled up in a rug and carried out of the house before being dumped in the garden with a note pinned to it with a knife.
  • The Case Of: Found in the season eight episode, "The Case of the Cross-Dressing Carp".
  • Casual Kink:
    • Grissom takes Charlotte on a date to see "The Wizard of Oz" played with Pink Floyd music, because he wanted to show her something different. Charlotte replies, "You want to be different, pin me to the wall and plant one on me like you mean it!" At the end of the scene, Grissom starts to leave, then pauses to ask, "Pin you to the wall?"
    • Sara needs to test out a theory about how a victim was restrained with duct tape, so she askes Grissom to "Tape me up?" Grissom, before following her to the lab, comments, "I love my job!"
  • Caught in the Bad Part of Town: "Getting Off" starts with the Victim of the Week driving a BMW into an area under the freeway. The next scene has him dead, with his car missing, as well as his wallet, watch and shoes.
  • Celebrity Paradox: In an episode of one of the early seasons, we can see the MythBusters making a cameo as extras. Fast forward to season 11 episode 2, there is a character exclaiming "What am I one of those Mythbuster guys? I don't know."
  • Celebrity Star: Many episodes feature at least one; the aforementioned Myth Busters, James Avery, Rascal Flatts, and Justin Bieber, just to name a few.
  • Cell Phones Are Useless: It becomes a plot point in "The Chick Chop Flick Shop" that the cell phone signal drops out at a particular point in the movie studio during a storm, allowing Ronnie to be cornered by the killer as her phone call to Catherine breaks up. Of course, this was an episode that was deliberately playing with a lot of horror movie tropes.
  • Chekhov's Gun: In "The Finger", Catherine and a man whose mistress has been kidnapped are sent to an isolated phone booth at an abandoned building to receive the next clue to her location. The phone has been vandalized, but the clue turns out to be a map in the phone book.
  • Chuck Cunningham Syndrome:
    • Detective Sofia Curtis was a recurring character during seasons 5 and 6, and actress Louise Lombard was a main cast member in season 7. But come season 8, Lombard left the series.
    • Most of the lab rat characters, (Archie, Mandy, Mia) disappeared from the show around 2007, although some stuck around until Ted Danson's tenure started. But so they eventually stopped appearing without any mention. Only Wendy (Liz Vassey) had an actual send-off.
  • Chute Sabotage:
    • In "The Descent of Man", the near-death of a skydiver whose parachute was sabotaged turns out to be connected with the deaths of two men who were killed from the sky. The skydiver actually sabotaged his own chute in an attempt to commit suicide out of guilt over his involvement in the two murders. It doesn't work.
    • In "Angle of Attack", the reserve chute on a pilot's wing suit is disabled before he is sent flying to his death. Except he was already dead. The sabotaged wing suit is an attempt to disguise the cause of death.
  • Circus Episode: In "Freaks & Geeks", the murder of a popular sideshow performer sends the team behind the scenes at a carnival freak show.
  • City of Adventure: It IS Las Vegas after all.
  • Class Reunion: In "Dead of Class", Dave attends his class reunion and has all of the typical run-ins with his former classmates. Then the festivities are disrupted when the former prom queen is murdered.
  • Clothing Combat: In "Alter Boys", one victim is shot and then strangled with his own necktie after the killer's gun jams.
  • Coffin Contraband: In "Maid Man", the ultimate goal of the killer is a cache of mob money hidden inside a burial niche in a mausoleum.
  • The Collector of the Strange: All the creepy crawlies in Grissom's office. There's also an irradiated fetal pig.
  • Color-Coded for Your Convenience: In "Long Road Home", a fingerprint is rendered visible on a document known to have been handled by a woman called "Tangerine". Even before her photo shows up on the AFIS computer screen, it's clear to viewers that it's hers, because the cyanoacrylate mist turns the print tangerine orange.
  • Color Motif: The original CSI has a lot of brown that evokes the desert setting of Las Vegas. CSI: Miami has a lot of orange and yellow to evoke the bright, sunny semi-tropics of Miami. CSI NY has blues and grays to evoke the gritty nature of the big city.
  • Comedic Sociopathy: Hodges, who would make a fine Magnificent Bastard if he weren't so grotesquely inept at everything that didn't involve forensic science.
  • Commuting on a Bus: Sara's right on the line between this and The Bus Came Back. She's listed as a regular, but not in every single episode.
  • Conspiracy Theorist: All of the victims and suspects in "Leapin' Lizards".
  • Constructive Body Disposal: The B-plot of "The Case of The Cross-Dressing Carp" involves a body being found when an old casino is demolished. Although it appears that the casino might have been built on an Indian burial ground, the body actually turns out to be an Intrepid Reporter who was snooping around a private mob party being held before the casino was officially opened. He was shot and dumped down one of the construction shafts which were then sealed off before the opening.
  • Consulting a Convicted Killer: Langston seeks the help of his nemesis, serial killer Nate Haskell, to catch the "Dr. Jekyl Killer". He isn't really that helpful and mostly just messes them around. His actual plan was to goad a guard into shocking him as to fall and break his own glasses... and using the broken arms from said glasses to stab Langston through the bars of his holding cell.
    • Well, he pointed them to the restaurant where they found the link between all of the murders and from there were led to the actual killer, so in that sense he was very helpful. But after that he just strung them along waiting for his chance to attack Ray, and milking his apparent knowledge for all it was worth.
  • Contortionist: "Sqweegel" can contort himself enough to fit into the spare tire compartment of a car. Instead of sticking to performance, he's expanded applications of this to murdering unsuspecting victims.
  • Contract on the Hitman: The Victim of the Week in "Passed Pawns" is ultimately discovered to have been a low-rent hitman murdered as a result of his activities.
  • Cool Old Guy: DB.
  • Coolest Club Ever: The setting of many of the episodes.
  • Cop Killer: Several examples in spirit, though not always in letter since the CSIs aren't actually cops in this show.
    • The Red Shirt who gets killed when Warrick leaves her alone at a crime scene in the pilot.
    • A random officer who's killed outside a burger joint...by another cop who claims it was an accident, but might have had a grudge ( it was dark and said cop was losing his vision).
    • Warrick Brown was killed at the end of a later season by The Undersheriff.
  • "Could Have Avoided This!" Plot: In "Anatomy of a Lye", a young hot-shot attorney tried to cover up what appeared to be a DUI hit-and-run when he allowed the pedestrian he hit to die while lodged in his windshield, then soaked his body in lye and buried him in a playground. But as it turned out, the pedestrian jumped out in front of his car in a suicide attempt. If he had just stopped and called 9-1-1, he probably would've gotten off scot free, or at worst with just a DUI charge.
    Sara: You were off the hook...
    Grissom: ...until you let him die.
  • Couldn't Find a Pen:
    • In "Passed Pawns, the Victim of the Week uses his dying strength to write the letters 'D E' in his own blood on the floor of the alley.
    • In "CSI Unplugged", the kidnapper leaves a note saying "WE HAVE HARPER" written in blood.
  • Cowboy Episode: In "The Good, the Bad and the Dominatrix", Lady Heather is dressed as a saloon girl when she is assaulted by a client dressed as a cowboy and left for dead on the grounds of a Wild West theme park.
  • Cramming the Coffin: In "For Gedda", the team investigates the murder of a man who was stuffed in an occupied coffin. The victim ends up being someone Warrick is familiar with.
  • Crazy Cat Lady: The victim in "Cats in the Cradle".
  • Crazy-Prepared:
    • Langston. This ends up working to his detriment.
    • Kevin Greer, the Blue Paint Killer, went as far as manufacturing fake evidence of a nonexistent victim so that if he were ever caught he could send the cops on a wild goose chase and use the distraction to commit suicide.
  • Creepy Child:
    • "Bad Words". A given when said child is a pyromaniac.
    • Sociopathic Teen Genius Hannah West from "Unusual Suspect" and "Goodbye and Good Luck".
  • Creepy Dollhouse: The ones made by the Miniature Killer.
  • Crowbar Combatant: In "Ending Happy", one of the elements in Happy's Rasputinian Death is being brained by a prostitute wielding a crowbar.
  • Creepy Twins / Sibling Yin-Yang: The Gig Harbor Killer, unemployed and lived alone on a boat, and his wealthy real estate wiz brother (they were adopted by separate families). It's implied they were already partners for the GHK murders and that the wealthy twin is using the "copycat" crime scenes to spring his brother. Additionally the elaborately staged crime scenes have hidden Gemini symbols (spots of blood and threads made of human body parts form the constellation, two crimes scenes are on properties belonging to sister companies named after Castor and Pollux).
  • Cut Apart: The fifth season finale uses this trope to deal a Your Princess Is in Another Castle! moment to a rescue operation.
  • Cyberbullying: One episode had the LVPD investigating the suicide of a young cheerleader — turns out that she was Driven to Suicide by the class' Alpha Bitch who created a webpage in which an edited video of the girl calling herself a slut played and she was harassed 24/7 by mocking texts from people all over the country because the page also had her phone number. As horrifying as it was, it was handled like many other Subculture of the Week episodes.
  • Dark Secret: Often the motive for many of the crimes.
  • A Date with Rosie Palms: A teenage girl disappeared, and while investigating the house, the team discovers one of her nightgowns is covered in her brother's semen. They suspect that he had something to do with the disappearance until Nick takes the boy aside and privately asks him about this trope. Turns out, the brother was doing the deed in the bathroom and simply grabbed the first item on the top of the clothes hamper, leading to his embarrassment when this is revealed.
  • Dead Animal Warning: In "Uninvited", the CSI team investigate when an entire family is reported as having been missing for a month. While investigating, they discover blood on the front doorstep, and eventually learn that the family dog had been killed and dumped there.
  • Dead Man Honking:
    • Happens when a drugged driver falls asleep at the wheel and runs off the road in "Jackpot".
    • Happens again in "Disarmed & Dangerous". A crook shoots at Brass and Ray from a moving car. Brass returns fire and kills the driver, and the car crashes into a parked car where the driver faceplants on the horn.
  • Dead Man's Chest:
    • In one episode, a spurned lover stuffs his ex-boyfriend's body in a trunk, which is kept in private storage. Problem is, the body won't fit, so he cuts off the head and leaves it in a car which is then stolen.
    • In "Long Road Home", a body is hidden in a gear box containing a set of drums and dumped in alley.
    • In "Immortality", Grissom is sent a limbless body inside a suitcase.
  • Deadly Road Trip: It involved a particularly dead-eyed gang of juvenile delinquents who beat up tourists For the Evulz, knowing that as juveniles they would face relatively short sentences if caught.
  • Deadpan Snarker: Count on one (or more) of the cast members making a pun right after the discovery of the body and just before the opening credits.
  • Depraved Dentist: The killer in “Sweet Jane” who used his job to pick his victims.
  • Death Dealer: The first Victim of the Week in "Last Woman Standing" is killed when his throat is slashed open by a thrown playing card.
  • Death in the Clouds: "Unfriendly Skies" (a panicking passenger is beaten to death in an airliner) and "Forever" (a race horse trainer is found dead in the compartment transporting the animal).
  • Decoy Protagonist: The pilot has Naïve Newcomer Holly Gribbs, fresh out of the training academy and ready to start her career as a CSI. She's shot by a suspect at the end of the first episode and dies from her injuries in the second.
  • Defective Detective: Hardly anyone on the cast doesn't have some personal demon: Grissom's nerdiness and hearing-loss scare, Sara's mother killing her abusive father and ending up in an institution, Catherine's work keeping her away from family, Brass' estranged daughter, Warrick's gambling addiction, etc.
  • Destination Defenestration: In "Stalker", Nick gets shoved out of window when he is surprised by the guy whose apartment he's searching, and winds up being hospitalized.
  • Dice Roll Death: One episode involved a woman who died by gunshot. During the course of the investigation, the team discovers that on the complete other side of town, a man had been target shooting in his backyard at the time of the death. It turns out that he had fired into the air, and the bullet had arced all the way into the victim's backyard, where she just happened to be at the time.
  • Dirty Cop: Vega, McQuaid, and one other FBI agent.
  • Dirty Harriet: Morgan goes undercover as a hooker in "Skin in the Game".
  • Disability Alibi: During the "Miniature Killer" arc, one suspect (the son of a murdered rock star) is cleared when they confirm that he faints at the sight of blood, therefore couldn't have left the crime scene let alone use some of the blood to adjust the miniature to fit it.
  • Disappearing Box: A woman seems to disappear for real in "Abra-Cadaver".
  • Disaster Dominoes:
    • In "Chaos Theory", the solution to an apparent kidnapping, murder and disposal of a body in the dumpster turns out to be nothing but this, and therefore not a murder at all. A college girl accidentally dropped an object through the garbage shut, went to the pail to retrieve it, a speeding car accidentally hit the pail, which injured her and caused her to fall inside, then her body was compacted and brought to the dump by the garbage truck. The episode ends with the victim's family being incredibly upset by the revelation and announcing that they will hire a P.I. to uncover the "real" murderer.
    • In "Random Acts of Violence", Warrick becomes convinced that the murderer of his old Mentor's daughter is his High School Bully All Grown Up, but all evidence pointing to him is circumstantial and he's released. When Warrick tracks him down to berate him, he is followed by his mentor, who beats the guy up, and gets himself arrested and charged with assault. This causes the neighborhood to close the facilities where the mentor coached local troubled kids and to disband their football team, implicitly making all those kids get into trouble later. It turns out that while the bully stole from the mentor's home, he was actually innocent of the murder.
  • Disgusting Public Toilet: "Disarmed & Dangerous" opens with a fastidious FBI agent entering the men's room at a filling station. The inside is pretty gross, with an unidentified liquid leaking on to the floor from a broken urinal. The agent then becomes the Victim of the Week and dies in the disgusting bathroom.
  • Disproportionate Retribution: Many killers engage in this, such as a teenage boy who beat his little brother to a bloody pulp for... telling his classmates he (the older brother) still wets the bed.
  • Do Not Call Me "Paul": D.B. Russell. Nobody calls him Diebenkorn. And Julie, who prefers 'Finn', which is short for Finlay.
  • Double Aesop: Frequently done with a guest character, to apply the moral of their story to a longer-running established storyline and/or to one of the main cast.
  • Downer Ending: "Alter Boys", "Homebodies", "Fracked", and of course "For Gedda". Really, any episode where they can't prove the suspect did anything wrong could be considered this.
    • "Bittersweet" had the culprit turn out to be a surviving victim from a serial killer that was imprinted on by her violator and ended up murdering her victims in the same fashion.
    • Just five episodes later, in "Crime After Crime," it's revealed that fairly major recurring character Detective Vega has gone Vigilante Executioner, and he commits Suicide by Cop.
    • "Trends With Benefits" seemed like it was heading this way. The rapist professor's victim didn't want to press charges and the other students he had sex with consented but somehow word gets out and the professor is suspended.
    • "Let it Bleed" ended with all of the suspects kiled execution style, courtesy of vengeful Colombian drug lord whose Mafia Princess daughter died due to an accidental overdose together with a botched blood transfusion to revive her.
    • A few episodes later, "Say Uncle" had the CSI team discovering that a young HIV-positive boy having shot his abusive mother to death, after the latter murdered his uncle in front of him, the only person who was nice to him and tried to take him away from her. The boy is sent to juvie as a result, and Grissom expresses regret that he solved the case.
  • Double Entendre: In "Lady Heather's Box" Lady Heather herself doesn't have any lockbox/safe/etc like the title suggests, making it pretty obvious what they really meant. note .
  • Driven to Suicide: In "Unleashed", pregnant teenage high school student Maria Diorio (played by Brooke Anne Smith) committed suicide by hanging herself with her lover's belt after various traumatic factors, such as her father's death, her pregnancy, her lover's refusal to help her at her time of need, and especially the fact that an Alpha Bitch and her friends, out of resentment that her lover, the homecoming king, dumped her for Maria, decide to get back at her by making obscene posts en masse, and create a website where they plant Maria's face onto a donkey with a caption stating "I'm a stupid bitch!", as well as a viral video that allegedly has her saying in cheerleading cheers that she's a whore, getting over 1,000,000 hits. Her baby however survives due to Doc Robbins coming to collect the body, realizing the baby isn't dead, and performing an impromptu emergency C-section and infant CPR.
    • In the episode "Goodbye and Good Luck" returning characters Marlon West and his Child Prodigy sister Hannah are the prime suspects again at their university when Marlon's girlfriend is found dead after being pushed out a window four floors up. As the case goes on both Marlon and CSI Sara Sidle believe Hannah killed Marlon's girlfriend on her own accord while purposefully framing him, and try to get a recorded confession from her when she next visits him in jail. Hannah is too clever to reveal she did it, but she does tell Marlon that she did it because him being imprisoned on a life sentence means she can be sure he'll never have other girls or anyone else in his life. Recognizing he's now under Hannah's control, Marlon hangs himself in his cell.
  • Drugs Are Bad: In "Let the Seller Beware", a cheerleader gets high on PCP and ends up eating her friend.
  • Dung Fu: During a Prison Riot in "No Humans Involved", the prisoners make an Excrement Statement by defecating on the floor, and then throw the excrement at the police officers who enter to break up the riot.
  • Dying Clue: In "Passed Pawns", the Victim of the Week writes the letters 'D E' in his own blood as he lies dying. Not that it helps the CSIs very much in the end.
  • Dying Dream: Working Stiffs: "I knew it wouldn't work..."

    E-L 
  • Eagle-Eye Detection: Grissom and Catherine provided the page image at one point.
  • Early Installment Weirdness:
    • In the first few episodes of the first season, Brass is openly antagonistic with the CSIs and acts as a cynical bureaucratic foil to the more idealistic forensic scientists (specifically Grissom). This completely changed with the ninth episode "Unfriendly Skies" which featured Brass helping the CSIs solve a case with no mention of their previously unfriendly relationship, and by the end of the season the character had been Retconned into the most important ally that the CSIs had in the police department.
    • The early episodes did not feature the Unnaturally Blue Lighting that would later define the visual style of the lab. The first season also has a completely different film stock than all the others.
    • The first five episodes featured a completely different coroner, a younger woman named Jenna, before she vanished with no explanation and was replaced with Doc Robbins, who remained with the show until its finale.
    • In the first season you would frequently see the CSIs picking up pieces of evidence with personal items (such as a pen). No real CSI would ever do this, as said personal item almost certainly has some of the owner's DNA on it and would interfere with a DNA test. Thankfully, this was completely dropped by the second season, possibly due to the writers learning better.
  • Edible Ammunition: The frozen meat bullets one perpetrator used to shoot his victim.
  • Edible Bludgeon: In "The Gone Dead Train", the Victim of the Week in the B plot is murdered with a pork chop; stabbed in the neck with the bone, to be precise.
  • Education Through Pyrotechnics: Complete with Adam and Jamie looking on in one episode.
  • Elevator Failure: Hodges and Henry get stuck when all of Vegas loses power.
  • Embarrassing First Name: 'Diebenkorn' Russell, aka D.B.
  • Enfant Terrible:
    • An 8-year-old not only kills and steals from the victim in "Cats in the Cradle", but also tries to incriminate her mother when cornered by the evidence.
    • The 12-year-old in "Go to Hell" is even worse.
    • The young killer in "Unusual Suspects" and "Goodbye and Goodluck".
    • Justin Bieber's character, a teenage Right-Wing Militia Fanatic out to avenge his brother who deliberately almost blows up Stokes; traps Willows, her detective boyfriend, and a cool bomb tech in a warehouse lined with explosive boobytraps; and convinces another adult to go along with all this. Oh, and he was a brat on the set.
  • Enhance Button: They once used a reflection in a young girl's eye in a photo to get an image of the location where the picture was taken (a boat).
    • A particularly egregious example happened when they showed off a 3D crime scene scanner. Such a device does actually exist, using a laser to create a 3D image of an area, but they then used the computer to lift the body off the bed to look at the stains on the sheets underneath it. It's the equivalent of taking an ordinary photographic image and being able to "strip away" the skin and muscles to get an image of not just the structure of the person's bones, but what color they are.
      • Theoretically, this could work, if they'd separately scanned the pattern of bloodstains into the computer, then had it apply this pattern onto the sheets of the 3D simulation. If so, it's a legitimate way to demonstrate how the stains were distributed underneath the body, once the sheets had been removed as evidence.
  • Enemy Within: Ray, and his struggle not to give in to his dark side.
  • Even Evil Has Standards: While Sqweegel may brutally murder people with dark, terrible secrets, he refuses to kill innocent people that may witness his crimes.
  • Everybody Did It:
    • "Unfriendly Skies", though it was actually self-defense; the delusional victim was trying, probably unintentionally, to bring down the plane.
    • "Tell-Tale Hearts". Unusual in that the CSIs have confessions from all suspects early on and have to learn who is telling the truth and who is lying... only to discover that all suspects did it together.
  • Everybody Is Single: Or at least to start with. Gil and Sara are now married. Warrick was married but the marriage fell apart. DB is married and mentions it at least Once an Episode. Doc Robbins is also married, as is his assistant, David Phillips.
  • Evidence Dungeon: In "Leapin' Lizards", the killer's barn is full of all kinds of evidence, including a Human Head on the Wall.
  • Evil Counterpart: Grissom used to hold fellow entomologist Dr. Mark Thayer in high esteem, and they even co-authored a scientific paper once. Since then, however, Dr. Thayer has become what Grissom describes as a "hired gun", selling his services to the highest bidder. When Thayer's testimony for the defense threatens to derail a high-profile murder trial, the D.A.'s office asks Grissom to try and refute Thayer's findings. Grissom eventually discovers that Thayer deliberately doctored the evidence to get the results he wanted to present, which would have given the jury cause for reasonable doubt. After Grissom explains his findings on the stand and destroys Thayer's testimony, an enraged Thayer comes up to him and accuses him of attacking his integrity. As they're arguing, the D.A. comes up to them and orders Thayer's arrest on charges of perjury and obstruction of justice.
    • To a lesser extent, Gil's counterpart on Day Shift, Conrad Ecklie. He tended to choose the "convenient" answer rather than the correct one and was more interested in advancing his career than finding justice.
  • Excrement Statement: During a Prison Riot in "No Humans Involved", the prisoners make an excrement statement by defecating on the floor, and then throw the excrement at the police officers who enter to break up the riot.
  • Exposed to the Elements: Inverted. Despite being set in Las Vegas, one of the hottest cities in the US, every character seems to wear black, leather, or some other outfit that would be ridiculously hot and uncomfortable. The now-defunct Gamer Jargon website called the inverse of this trope "CSI Wear".
  • Extra Y, Extra Violent: Referenced in one episode; a couple knows their son has this condition and constantly treats him with suspicion because of it. When their daughter accidentally kills their other son by pushing him down the stairs, she claims he did it on purpose; this is what actually turned him violent.
  • External Combustion:
    • In "Cat's in the Cradle", the B-plot involves a bomb planted in a woman's car that explodes when she stops at a garage to investigate a strange noise the car is making. It's revealed to be a plot between the woman and the mechanic, who she was cheating on her husband with, to try and get the husband sent to jail for attempted murder.
    • A simple time bomb left in the boot of a cheating husband. Unfortunately an unexpected detour means the bomb takes several bystanders with it.
    • In "Hog Heaven", an undercover cop is killed by a bomb planted in her car.
  • Fair Cop: Yowza! Sofia Curtis, Vartann, Lockwood, Sofia Curtis, that lady cop Nick dated for a second in Season 1, Sofia Curtis...
  • Faking the Dead: DB and Catherine come back to the morgue in body bags to escape the hitmen who are after them.
  • Fatal Flaw: Warrick's gambling problem. Grissom's hearing impairment also counts, though that was corrected with surgery at the end of Season three. Ray's inherited violence tendencies.
  • A Father to His Men: Grissom's markedly paternal leadership style, most visible with Greg, Nick and Warrick — especially right before Warrick gets killed, and afterwards. DB is getting into this now. His group meetings are "family meetings".
  • Felony Murder: Happens way too often to many criminals, who think they will just be charged with a lesser crime just long enough for it to be a Hope Spot.
  • Fiery Coverup: In "Grissom's Divine Comedy", a gang torches their leader's apartment to destroy an evidence before the CSIs can search it.
  • Fille Fatale: The principal villain in "Coming of Rage" is a high school girl who manipulates three of her fellow students into brutally murdering a fourth, while she stands by cheering them on.
  • Finger in the Mail: One episode featured a man who had found the cut-off index finger of his mistress in her apartment. Later, they find the body and it is revealed that it was the man himself who had killed her. To avoid suspicion of the murder, he staged it as a kidnapping gone wrong.
  • Fixing the Game: In "Lying Down With Dogs", one of the suspects in the murder has been drugging the dogs involved in the dog fights.
  • Follow That Car: In "Cockroaches", Warwick arrives back at the strip club in a cab (after having been ordered away). Seeing the woman he wants to talk to getting in another cab, he immediately tells his driver "Follow that girl".
  • Follow the Leader: The show precipitated a host of forensic science shows, even to the point that shows not inherently about forensics now spend more time on the subject (e.g. the medical examiner on Law & Order: Special Victims Unit).
  • Food and Animal Attraction: Exploited in one episode; a woman going through a messy divorce wipes bacon grease on her hands to spite her husband after agreeing that his beloved dog would live with whomever it "chose". He then proceeds to attempt to sneak in and replace the dog with another, so she shoots him. The sound of the gunshot causes the replacement dog to go berserk and tear her throat out.
  • Food Porn: The dishes in "Last Supper", until chefs guess the secret ingredient ("It was supposed to be kangaroo!").
  • Forced Out of the Closet: One episode featured a football player who was outed during an investigation. One of the straight female investigators gets called out on this, but she fails to see why it's such a big deal.
  • Forensic Drama
  • Frame-Up: The plot of the 2021 revival is a kidnap case leads to a lab that seems to show Hodges has been faking evidence in thousands of cases. Sara, of course, knows Hodges could never do this but the newer CSI techs aren't sure and the D.A. wants Hodges arrested. Worse is how this would mean every case Hodges ever had a hand in is now suspect and open for appeal.
  • From the Latin "Intro Ducere": It had one when Grissom investigated the death of a man who had Down's syndrome. After catching the murderer, Grissom calls back to an earlier conversation where the murderer called the victim a "retard" (Grissom corrected him, of course) and informs him that "retard" means "to hinder", so the killer's life "just got retarded".
  • Gambit Pileup: The crime of the week in "Suckers" is a very good example: it's an Insurance Fraud concealed within a faked Oceans Eleven-style heist that had a faked murder as a distraction. Grissom even points out to the mastermind (the hotel's manager) that there is not enough evidence to convict him, but they will send it all to the insurance company regardless in the hopes that it will be a Pyrrhic Victory.
  • The Gambling Addict: Warrick.
  • Game of Nerds: Grissom is a baseball fan.
  • Giant Wall of Watery Doom: Spells doom for a Victim of the Week trapped in a storm drain during a flash flood in "Down the Drain".
  • Gorn: The TMI-cam.
  • GPS Evidence: Often. As an example: in the season five finale, "Grave Danger", Grissom, Entomologist Extraordinaire, determines Nick's location from the ants in his box, since fire ants can only be found in nurseries in Nevada, which means that the soil... you can figure out the rest.
    • Punningly used in the episode "Fracked", with literal GPS data.
  • Grand Finale: The series is wrapped up with the Finale Movie "Immortality." The crime of the week was just big enough that it warranted a two-hour episode to solve, but the truly important thing was that Sara finally got over her decision to separate from Gil (that is the reason she returned to Las Vegas to begin with) and thus both Grissoms go Riding into the Sunset.
  • Grievous Bottley Harm:
    • In "The Case of the Cross-Dressing Carp", the Victim of the Week attacks himself with a broken beer bottle; hacking at unwanted breast tissue on his chest before committing suicide.
    • In "Meet Market", the Victim of the Week is bludgeoned to death with a champagne bottle.
  • Ground by Gears: In "Hero to Zero", the second Victim of the Week is crushed to death in the winching mechanism of his truck in an attempt to Make It Look Like an Accident.
  • Halfway Plot Switch: One episode begins with the team re-evaluating a case after the perp claims he had been forced to confess by a Rabid Cop. Despite everyone stressing the need to prove the perp's guilt in this specific case in order to uphold the detective's integrity and avoid setting precedent for all the other people who the detective arrested to have their sentences overturned, they find themselves unable to definitively do so and instead start working on another unsolved case because they decide that they cannot allow the felon to be released.
  • Happily Married: Gil and Sara, though it's a long distance marriage. D.B., is the first CSI to start on the show with a wife and family.
  • Hard-Work Montage: This show does this to show the characters doing the hard work of forensic investigation at the lab. In the episode "I Like to Watch", they do some Lampshade Hanging: Hodges looks forward to a certain test, as he thinks it will be good material for the documentary crew currently in the lab. Nick points out that the test takes six hours, to which Hodges remarks that "When they cut it together, it'll only take thirty seconds." It takes thirty seconds. Also known as "Microscope montage".
  • Hazardous Water: Murder in a cloudy swimming pool.
  • Heel–Face Turn: Although he was originally introduced as an antagonistic character, Conrad Ecklie has since undergone considerable Character Development (especially in season 12, in which his estranged daughter moves from L.A. to join the team) and become a much more sympathetic character.
  • Helium Speech: In "The Finger", a kidnapper inhales helium capsules to disguise their voice when making ransom demands.
  • Heroic Bystander: Civilians have helped the CSIs on multiple occasions either by finding evidence that helps break a case or even by catching the criminals in a chase.
  • High School Rejects: The standard stoners and malcontents that are always the first suspects.
  • Hoist by His Own Petard: A woman that was planning to poison her boss and ex-lover with ricin accidentally spills it over her pens. Not bad, if it wasn't for the fact she had an habit of biting her pens...
  • Hollywood Exorcism: "Go to Hell". Justified, since the guy performing it is a self-made "priest" with no actual church affiliation and little idea about everything.
  • Hollywood Nerd: EVERYONE. One of them is even supposed to be an ex-stripper!
  • Hollywood Science: Never take anything presented as science on any of the episodes as even remotely factual unless you verify it first. In fact, the illusion of accuracy in this manner is causing some issues...
    • In the earlier seasons, the show prided itself on portraying science relatively accurately (though Miami didn't); even the seemingly-nonsensical "acoustic archaeology" that solves the case in "Committed" has factual basis. This changed in later on, the most egregious example likely being a computer program that can apparently delete things out of photographs to see what's behind them.
  • Homage: "Blood Moon"'s opening opts for sex and violence rather than sparkly vampires and werewolves.
  • Hood Hornament: Grissom investigated the case of a man with Down's Syndrome who was working at a ranch. The murder weapon turned out to be a pair of these, and the killer their owner, a cocky ranch hand.
  • Hood Ornament Hottie: In "4 x 4", Catherine and Warwick investigate the murder of a 'convention girl' (a.k.a. a 'booth babe') at the International Vehicle Convention.
  • Hooks and Crooks: The weapon of choice for the Gig Harbor Killer is a fishing gaff (as seen in "The CSI Effect").
  • Hot Scientist: Practically all of the CSIs and the lab techs.
  • Human Head on the Wall: "Leapin' Lizards". They found a missing woman's head mounted on the wall like a trophy animal. She was murdered by UFO believers who were convinced she was a Reptilian queen.
  • Human Mail:
    • In "Helpless", a woman had herself packed into a box and shipped to her lover as a way of generating a sexual thrill. However, because her lover had been murdered, there was no one to let her out at the other end and she died.
    • In "Nesting Dolls," the bodies of two women are found in a makeshift grave. The first one is, in fact, a homicide, but the second turns out to be an illegal immigrant who attempted to literally mail herself to the U.S. and died in the process.
  • Humiliation Conga: Langston's first day is a non-villain example.
  • I Am Not My Father: Ray tried desperately not to become his, due to the man's violent tendencies.
  • I Am Spartacus: In S12, Ep2, "Tell Tale Hearts" The team run afoul of this trope when three different individuals confess to a multiple homicide. Two of them are guilty and the third, who ultimately commits suicide, was an Accomplice by Inaction.
  • I Ate WHAT?!:
    • In "Crow's Feet", the victim was engaging in urophagia, aka urine drinking for medical purposes.
    • In "Last Supper", contestants on a cooking show realise that what they are eating during a palate test is human flesh when one of them finds a contact lens in her mouth. She does a Spit Take on realising that she has a human eyeball in her mouth.
  • Identical Twin Mistake: One episode deals with the Victim of the Week being a soccer mom that was shot in a parking lot, and the investigation eventually leads to a house where the woman's identical twin has apparently hanged herself. Turns out that the women were long-lost twins and the one who apparently committed suicide had become a newspaper editor and was about to rat out a photographer that had photoshopped pictures of the Second Gulf War to "make them more representative of War Is Hell", winning a prize for that. He had shot the first twin by mistake due to them having gone to the same laundromat and her arriving at the time he had expected his target to be there. He then went to her house to take care of the evidence of his forged photos, and when the "dead" woman came home, he panicked, strangled and then hung her.
  • I Have Your Wife: A particularly convoluted example is used in "Buzz Kill". A woman's brother is kidnapped and she is forced to deliver a message to the owner of a marijuana dispensary, showing that his wife and children have been kidnapped, and demanding he turn over all the cash in the shop.
  • I Just Shot Marvin in the Face: Several examples.
    • In "Coming of Rage", Nick Stokes investigates how a woman got shot with no evidence of a shooter anywhere near. The answer is that there was an idiot who had a gun and made a shooting range in his backyard, which is in the suburbs and within city limits, a big-time city ordinance no-no. A stray bullet went into the air and struck the woman on the decline. When they arrest him, he protests it was an accident and Stokes contemptuously responds, "Well, that's why it's illegal to shoot guns within city limits, genius!"
    • In "Fur and Loathing", a hunter fails to follow one of the most important rules of shooting things — always positively identify your target. So, when a drunken guy stumbles out of a Furry convention wearing a raccoon suit and wanders out into the desert, the hunter takes him down, thinking the victim was a coyote. The episode is vague on whether or not he'll get prosecuted for it, although it leans towards "no" since it was pretty dark at the time.
    • Averted in the episode "Better Off Dead", when Greg is sharply scolded by Bobby Dawson, the lab's ballistic expert, for failing to properly clear a gun gathered in evidence. There was a bullet left in the chamber because Greg had mistakenly assumed that all the guns recovered from a broken gunshop counter were unloaded, as required by law. Both Greg and Sara look obviously rattled at this clear breach of gun handling protocol, and no-one in the lab relaxes until Bobby Dawson verifies for himself that the gun is, in fact, now properly unloaded.
    • In "Disarmed and Dangerous", a suspect in the murder of an FBI agent accidentally shoots himself in the head in the middle of a crowded arena while trying to show everyone that the gun he had taken from Brass wasn't even loaded. He thought it wasn't loaded because the FBI agent he had killed was really just a crazy guy pretending to be an agent running around with an empty gun, plus he was delirious and on a drip at the time for ripping an entire necrotic bicep out of his arm.
    • The episode "A Night at the Movies" possibly has the most extreme example of this Trope in the series, the CSI Las Vegas Team investigates the case of a young man who was shot fatally with one bullet in a shed that was riddled with hundreds of bullets, thinking at first that it must have been some weird gangland hit. Turns out, it was the inevitable result of a bunch of idiot teenagers playing games with a loaded, automatic MAC-10 by having someone standing on a second story balcony spin the gun down on a metal pole and the others would try to dodge the shots.
    • In "Malice in Wonderland" a robber managed to kill a man with a blank round when he put the gun to the victim's head and pulled the trigger. The blast propelled a button on the victim's hat into his brain.
  • Imaginary Love Triangle: A mother in "Turn of the Screws" believes she's in one and thinks her daughter tried to steal her boyfriend, causing her to snap and kill her.
  • Imagine Spot: In the Season 13 premiere, we see DB imagining his granddaughter and Flynn in the morgue, him killing McKeen (the corrupt cop who orchestrated his granddaughter's kidnapping), and his wife getting fed up with his disturbing job and leaving him.
  • Impaled with Extreme Prejudice: In "The Chick Chop Flick Shop", the first Victim of the Week is impaled when she falls onto a movie prop consisting of sharpened lengths of steel pipe.
  • Impromptu Tracheotomy: In "Ending Happy", this was one element in the titular character's Rasputinian Death, delivered via a crossbow bolt. Ironically, since the victim was choking due to anaphylactic shock at the time, his windpipe being opened gave him enough time to reach his epi-pen. The bolt also managed to miss everything else in the victim's neck by pure chance.
  • Incessant Music Madness: One case involves a garotted musician. Turns out he was killed by an angry neighbour who couldn't stand the noise.
  • Inconveniently Vanishing Exonerating Evidence:
    • In the episode "Who Shot Sherlock", it's set up to make it look like the victim did this by attaching a gun to a piece of surgical tubing. It turns out the killer did this to make it look like a suicide set up to look like a murder. In the same episode, Sanders mentions that the families of suicides will often hide the gun to avoid the stigma.
    • One of the many fallouts in the two-parter "A Bullet Runs Through" comes from the cops apparently shooting an unarmed suspect; it turns out that the cop turned around and saw him with a gun just as he was moving to throw it, meaning it was thrown on a roof as he was shot.
    • In the episode "Homebodies" a man attempts to disguise his suicide as murder by tying balloons to the gun so it floated away.
  • Indian Burial Ground: In the B Story of "The Case of the Cross-Dressing Carp", a skeleton is found on the site of Sam Braun's old casino as it is being demolished. When Sara investigates, she finds Native American artifacts near the remains, she calls a halt to everything until their origins can be determined. The developers are worried that the site is a Native American burial ground; not because of any curse but beacuse if it is, the whole project will have to be shut down until a complete archaeological examination is conducted. However, the bones turn out to belong to a reporter who was murdered in 1964 while dressed in a Native American stage costume, and whose body was dumped in the casino foundation.
  • I Never Said It Was Poison: In the B Story of "Slaves of Las Vegas", Warrick and Sara ask a suspect in a robbery to show them his car. He does so and then says "See! It's not even the same model!" Sara then points out that they hadn't told him what model they were looking for.
  • Initialism Title: For "Crime Scene Investigation".
  • Inn of No Return: "Check In and Check Out" features a modern take on the trope, with a particular room in a sleazy motel where five brutal murders take place in a space of weeks. It turns out the voyeuristic owner has been dosing the guests in that particular room with LSD to observe the results, which are often fatal.
  • Inside Job: An episode has the team investigating an officer-involved shooting during the robbery of a grocery store. When the surveillance tapes reveal that there was much more money in the registers than store policy recommended, suspicion quickly falls on the cashier on duty, who soon admits to being in league with the robbers.
  • The Intern: Greg, when he decides to leave behind life in the lab to become a CSI.
  • The Internet Is for Cats: Dr. Robbins appears in one episode laughing at internet cat memes.
  • Interservice Rivalry:
    • Regular LVPD vs the Crime Lab. The LVPD often see the lab team as a bunch of science nerds. Even Brass was not happy being assigned there in the beginning.
    • The baseball ep had the LVPD playing another group.
  • Intoxication Ensues: Played for drama in "Check In and Check Out" when Hodges unknowingly gets dosed with aerosol LSD while investigating a crime scene, and attacks Henry.
  • Iris Out: The ending of "Wild Life" does this with the parrot.
  • It's Personal: Seasons often start and/or end with an "It's Personal" episode.
    • In the episode "Random Acts of Violence", Warrick is processing the scene of a suburban drive-by shooting, at which a young child has been shot and killed. Upon discovering that the child's father is a close friend (known to be an admirable and honorable person generally), Warrick does his best to comfort the grieving father. Aware of this connection, Grissom arrives and checks on his colleague:
      Grissom: You going to be able to handle this?
      Warrick: ...I want this case.
    • In early seasons, even if there weren't a direct relationship between the investigators and the criminals the nature of the crime would often make the investigator take it personally themselves. For instance: domestic abuse, or overall violence towards women? Sara would sympathize. Broken marriages, or mothers (especially the working kind)? Catherine. Damaged childhoods? Nicky. Grissom himself explicitly stated that drug dealers and people who harm children make him furious.
      "You prey on innocent children, and you think we came all the way out here to bust you for possession, you dumb punk?!"
  • It Works Better with Bullets: In "Forget Me Not", Ronald Basderic attempts to shoot Sara only to find that Detective Crawford had swapped the clip from his gun for one loaded with blanks when he searched him earlier.
  • Jack the Ripoff: "The Execution of Catherine Willows".
  • Jammed Seatbelts: In "Bloodsport", one Victim of the Week is a woman who is Trapped in a Sinking Car by a jammed seatbelt, and who drowns after she accidentally shoots a man who is attempting to rescue her.
  • Jealous Parent: In episode "Turn of the Screws", a murder suspect turns out to be the mother of a 13-year-old daughter, who murdered her out of paranoia and jealous belief that the girl was trying to steal her younger boyfriend. Catherine berates the mother because of this.
  • Job Mindset Inertia: A recurring antagonist in early episodes was a heavy handed cop who served in the US Army and had an unfortunate habit of acting like he was still in a warzone (although he toed the line from actual Police Brutality).
  • Jumping on a Grenade: In "Targets of Obsession", a bomb tech puts his body over a bomb that's about to explode to save the three other people locked into the warehouse with him. He succeeds in saving the other three at the cost of his own life.
  • Jumping the Shark: In "Two and a Half Deaths", Brass tells Grissom that he feels Annabelle jumped the shark when its struggling single mother main character won a fortune in the lottery. Grissom has never heard the term, so Brass starts to explain it when they are interrupted by a scream.
  • Just a Flesh Wound: Catherine is shot in the side, cauterized with a curling iron, and still able to keep running from the bad guys.
  • Justified Criminal: Eventually subverted—the bank robber claims he's doing it for his family, but he's lying.
  • Justice by Other Legal Means: In one episode, where a man gets 4 years for killing a supposed child molester, only for it to turn out he was the child molester, and the victim was going to report him. Once the team uncovers the truth, they inform him he's facing a mandatory sentence of life without parole for sexually assaulting a minor.
  • Just One Little Mistake: How most perpetrators get caught.
    • A subversion in the episode "Killer":
    Sympathetic Murderer: So where did I screw up?
    Grissom: You killed two people.
  • Karma Houdini: A typical CSI Downer Ending will likely involve one of these, the most horrifying examples being Kelly James from "Homebodies", a robber and rapist who not only walks, but murders the only person who could finger him; the gas company from "Fracked", who drove an old farmer to suicide after poisoning all his animals; and Gina from "Bittersweet", who served five years in prison as an accessory to murder, only for new evidence to come to light that she was the dominant partner, and she's protected by double jeopardy. She's suspected of being the episode's killer, and not only is it not her (it's her traumatized last victim), but the Papa Wolf of one of her victims goes to jail for beating her half to death.
  • Karma Houdini Warranty:
    • A very long example: in the first season episode "Too Tough To Die", Tony Thorpe rapes and beats up a woman so bad she is left braindead, but, as she's technically still alive, it's not murder so he only gets a few years. In season 9 when Sara comes back we find someone pulled the plug on the victim. While Thorpe is suspected at first, it turns out he got in a gun fight and ended up paralysed from the waist down. Couldn't have happened to a nicer guy.
    • Deconstructed in "Sweet Jane" with David Lowry. He might have finally been caught and convicted for his murders after decades as a free man, but he's been a Karma Houdini for so long that he's had a full and satisfying life and is so old by this point that he's likely to die before he even sees the inside of a prison cell. So even if his warrenty has expired he has lived what he considers a wonderful life, much to the team's anger.
  • Karmic Death:
    • A divorcing husband and wife are arguing over custody of his beloved pet dog. He gets an identical dog and tries to sneak it into her house. She catches him in the act and shoots him, but that's not the karmic part. That would be when the new dog turns out to have been abused, goes berserk at the sound of the gunshot, and rips her throat out.
    • A scammer that made a living selling the same exhausted mine once and again kills a man that knew too much and decides to disguise it as a mining accident. He fails to leave before the fuse burns down and gets impaled in the brain by a flying wooden stake.
  • Killed Off for Real:
  • Killer Rabbit: Can we ever look at cornmeal the same way?
  • The Killer Was Left-Handed: Repeatedly, both with literal left-handedness and with problems with DNA in saliva.
  • The Lab Rat:
    • Greg Sanders, whose nickname at Television Without Pity inspired this entry's title. He has, however, now become a CSI in his own right.
    • Later seasons have made more use of the other Lab Rats - David Hodges (Trace), Archie Johnson (Audiovisual), Henry Andrews (Toxicology), Mandy Webster (Fingerprints), Bobby Dawson (Ballistics), Ronnie Litra (Questioned Documents), and Wendy Simms (DNA). The show has given them two Lower Deck Episodes with the appropriately-entitled Lab Rats and the hilarious "You Kill Me".
    • Unlike most Lab Rat characters on the CSI shows, Hodges is quite content to remain indoors and hates going into the field.
  • Lampshade Hanging: After ten long years, they finally poke fun at their periodic explanations of how a test or piece of equipment works for the benefit of the audience, even though there's no good reason for, say, Sara to be telling this to Nick in the course of everyday work.
    • Lampshades were also hung about being a forensics series in "I Like to Watch". Grissom tells the crew of a forensics Reality Show that there are too many forensics shows, and Hodges remarks that a six-hour laser ablation test will only take 30 seconds on TV when the show's editors re-cut it...just before a montage of him doing the test that's exactly 30 seconds long.
  • Laser-Guided Karma: In "Deep Fried and Minty Fresh," a restaurant owner is found dead from blunt force trauma on the floor of his kitchen. When searching the scene, the investigators discover a second body, a younger man covered in severe burns, in the dumpster out back. Turns out that the owner had attempted to rape a young woman who worked for him, only to be caught by her boyfriend. He helped his girlfriend escape, but was overpowered by the owner, who murdered him by shoving him face-first into the fat frier. The bastard dumped the body out back, re-entered the restaurant through the kitchen...and slipped on the wet floor, cracking his skull open on impact. Couldn't have happened to a nicer guy.
  • Laser Sight: In "Keep Calm and Carry On", Sara tackles Nick to the ground when a red dot appears on his chest while they are investigating a crime scene outside the airport. It turns out just to be Jerkass with a laser pointer.
  • Last-Name Basis: Grissom (even by Sara, his girlfriend/wife), Hodges, Brass, Ecklie, McKeen, occasionally Russell. Julie prefers 'Finn', short for her last name, Finlay.
  • Lawman Gone Bad: The team investigates a series of killings related to the murder of a mob boss many years before. It's mentioned that a patrol officer called in the car crash/body but mysteriously vanished along with the ill gotten gains and the possibility of this trope is discussed. It turns out that the corpse that was thought to be the mob boss's was actually his; killed in order to serve as a decoy.
  • Laxative Prank:
    • Investigating a death during a high-stakes poker game, the heroes discover that the waitress put eyedrops in the victim's drink as payback for him being a lousy tipper. She'd meant to give him diarrhea and force him to leave the game early, but he died before they kicked in (because the chemical in the drops reacted with the absurd amounts of lead in his system courtesy of eating several pounds of African chocolate a day for years).
    • In "A La Cart", the Victim of the Week is stabbed to death while dining in a blacked-out restaurant. Another table consisted of four brothers who keep playing pranks on each other. One of them aggravates Brass by continually having to dash of to the toilet. While he is out of the room, the other three brothers reveal they spiked his beer with a laxative while the restaurant was dark. This has no bearing on the case, does mark all four brothers as being tremendous Jerkasses.
  • Left Hanging:
    • "Bad to the Bone". Six or seven sub-threads, none of which were even close to being resolved.
    • Pretty much every season finale since season 7 has been this way as well. They love their end-of-season cliffhangers.
  • Life-or-Limb Decision:
    • One episode begins with finding a dead woman who was missing a hand. They eventually find that she had bitten it off to escape from a psycho's basement.
    • In "Consumed", it looks like a cannibalistic serial killer chewed through his own wrist in order to escape, leaving his hand handcuffed to the inside of a car. It was actually staged to allow the killer to exaggerate his mystique.
  • Lights Off, Somebody Dies: "A La Cart" features a restaurant where clients dine in absolute darkness, served by blind waiters. While dining, the Victim of the Week is stabbed through the temple with a pen.
  • Like Brother and Sister: Gil Grissom and Catherine Willows.
  • Limited Advancement Opportunities: Avoided. Though the cast has remained more or less constant, their relative rank and internal structure have been adjusted, including Brass's handing over the department to Grissom (and going back to being a detective), the race between Warrick and Nick to achieve CSI 3, and Ecklie's breakup of the team into two different shifts, which prompted the promotion of Catherine Willows to supervisor, and made room in the ranks for Greg to go from lab tech to field agent. Later on, Nick gets promoted to Catherine's right-hand man and Ray has progressed rather rapidly from starting out at entry level.
    • A particularly nice touch in Greg's case was Grissom making sure he really did want to make the lateral (and downward!) jump from Senior Lab Tech to extremely junior Field Investigator, reminding him that he'll be taking a substantial pay cut and that it will take quite a while to get back to his present level.
  • Living Lie Detector: FBI Cybercrimes Agent Ryan. Unfortunately, the criminals she hunts are anonymous internet users; fortunately it's very useful for startling people into doing what she wants (when a military pilot complains that he's not her chauffeur she points out that his "schedule" is to a tropical island with a woman who isn't his wife and— "Welcome aboard").
  • Locked Room Mystery: One episode involved a murder committed where all the doors and windows were locked securely from the inside. The killer was a cable installer who unlocked a window to a hidden attic while working in the house.
  • Long-Runner Cast Turnover: Since the original premiered in 2000, its later seasons have seen the departure of three of its leads (Grissom, retired, and Catherine, new job, and Ray Langston (who replaced Grissom), forcibly resigned), two of its secondary leads (Sara, quit from PTSD but now Commuting on a Bus, and Warrick, Killed Off for Real) and a number of its recurring supporting roles (Wendy, Sofia, and the very short tenure of Riley, meant to replace Sara). Most of the departures were of the "actor wanting to move on" variety, but contract disputes and in Warrick's case, personal problems, also factored.
  • Long-Runners: Fifteen seasons before being cancelled in 2015.
  • Look Both Ways:
    • In "Turn On, Tune In, Drop Dead", a college kid coming down from a bad trip runs away from the cops and straight into the street where he gets run over by a car.
    • At the start of "Cockroaches", a hitman fleeing from the cops runs down a laneway and gets run down by a car coming the opposite direction.
  • Lotsa People Try to Dun It: A extreme example occurs in "Ending Happy". The CSIs are investigating Rasputinian Death of boxer Lorenzo 'Happy' Gonzales, and discover a bizarre chain of events where the multiple murder attempts ended up interfering with each other. The drugged-up ex-boxer passes out on his favorite prostitute's bed, and is injected with snake venom by her and an accomplice. His boss's wife is fed shrimp by his boss, in order to trigger Happy's allergy when they hook up, causing his throat to swell. He's then shot through the throat with a crossbow by one of the people who injected him with snake venom, allowing him to breathe again. He figures out what the prostitute did and goes back to her room angry, and she hits him with a crowbar. Then he staggers off to rest on a chair by the brothel's swimming pool, and leans over to pick up a cigarette. The chair collapses under his weight and drops him into the pool, wherein he finally drowns.
  • Lower-Deck Episode: "You Kill Me" and "Lab Rats", both featuring the lab techs.
  • Luke, I Am Your Father: Catherine's dad was a recurring casino owner who regretted not taking responsibility sooner, although the two were very close. This soured when Catherine found out that he had someone (probably a bunch of someones considering it was old Vegas) murdered; they managed to patch things up a little before he was murdered and she now refers to him as "my dad".

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  • Mad Doctor: Serial killer with medical experience, 'Doctor Jekyll'.
  • Madwoman in the Attic: In "Go To Hell", parents imprison their daughter in the attic when they believe she is possessed.
  • The Main Characters Do Everything: Literally every possible police-related duty except handing out traffic tickets. It practically feels like the CSI team is an entire police department comprised of a dozen people.
    • This show is pretty bad about this. In real life, CSIs simply go from crime scene to crime scene collecting evidence; they don't do lab work. Right off the bat, a CSI's job is combined with a forensic scientist's job. They especially don't interview, interrogate and arrest people, even in cities where the CSIs are police officers, they don't interview and interrogate people. Even Captain Jim Brass, the only actual main character with a badge, wouldn't be doing investigative work. The rank of Captain is a management rank, he'd spend most of his time at the station performing administrative duties.
    • The combination of the CSI and forensic scientist jobs is due to California Doubling. The real-life criminalist(s) who were involved in the development and consultation of the show in its early years mostly worked in Los Angeles, where most criminalists both collect evidence from crime scenes and do lab work.
  • Make It Look Like an Accident: Inverted in "The Chick Chop Flick Shop". The victim (a horror movie actress) broke a heel and died by falling on a sharp pipe, but the owners of the studio intentionally tried to make it look like a murder and frame a former special effects employee who was badly burned when a smoke machine malfunctioned so that they wouldn't lose their liability insurance and be forced to close the studio.
  • Makeover Montage: The Teaser to "Under My Skin" has a teenage girl undergoing a makeover from her older sister. As this is CSI, it does not end well for her.
  • Mama Bear: Catherine "Don't mess with Lindsey" Willows.
  • Manipulative Bastard: The online "partner" of a troubled kid who shoots up the LVPD who turns out to be a cop who had had enough of both her (allegedly) abusive cop husband (she sets it up so he's the first one shot) and her (allegedly) stalker-y "SWAT" lover (she used his computer to frame him as the "partner", plus he'd kill the kid). Ironically they came into contact because the kid's mom wanted to help her son after his only friend was shot by cops and signed him up for (among other things) an LVPD youth outreach program.
  • Man on Fire:
    • "The Book of Shadows" opens with a student shooting a video in his high school corridor which is interrupted when one of his teachers comes running along the corridor on fire, before falling the ground dead.
    • In "Abra Cadaver", a Stage Magician goes up in flames while performing a trick on stage.
  • Married to the Job: Both Sara and Grissom.
  • Masked Luchador: In "Mascara", one of Langston's former grad assistants is murdered. He discovers that she was investigating Mexican wrestlers to solve a series of unsolved murders.
  • Medication Tampering: In "Primum Non Nocere", the team doctor for an ice hockey team murders the Victim of the Week by swapping his painkiller tablet for a quinine tablet that he knows will interact fatally with the player's heart condition.
  • Mind Screw: The episode "Blood Drops" from season 1. The father sexually abused his own daughter, which caused her to give birth at thirteen. Now, without even knowing that he even abused his daughter's daughter, this is hard to understand. He sexually abused his own daughter, who gave birth to a daughter, making him the father of both daughters, with the first daughter as both a daughter and a mother to the same father, so he's actually a father and grandfather to his own daughters. Yeah, it was as hard to understand as it was to watch.
  • Mistaken for Badass: Happens on a few episodes, but as an example: "Better Off Dead" has one of the people put in the hospital because of Mr. Trent's Plague of Good Fortune calls him a "Terminator"-style unflinching machine, completely unafraid of death (even as he's describing it, a cut to another location shows some thief with a switchblade being scared off from Trent's lack of response to his threatening). Turns out that Trent is a suicidal man on a quest to get killed, but the universe itself seems to conspire against him on this.
  • Mistaken for Cheating:
    • Doc's wife, when a body turns up in her bed. It was really a set-up, with a wrong place, wrong time kind of feel.
    • In "Turn of the Screws", a jealous mother suspected her daughter of trying to steal her younger boyfriend. Turns out he was just giving her a ride home from school.
  • The Mob Boss Is Scarier: An episode had a hitman refuse a deal to name the man who hired him in exchange for not facing the death penalty, figuring he'd live longer on death row.
  • Money to Burn: In "Neverland", a teenager makes $200 off the death of his friend. When another friend finds out what he has done, he attacks the teenager and then takes the money and burns it, considering it to be blood money and wanting no one to profit from it.
  • Monster Fangirl: Nate Haskell's "fiancée" in "Targets of Obsession".
  • Monumental Theft: In "Stealing Home", the CSI team investigate when an entire house is stolen.
  • Mood Lighting: To the point of absurdity; autopsies and lab work are often performed in near total darkness!
  • Morning Sickness: In "Primum Non Nocere", Grissom picks a suspect as being pregnant when she vomits at a crime scene. The suspect herself says that it is food poisoning, but Grissom points out that the window for food poisoning manifesting had passed.
  • Motor Mouth: Ronnie Lake, Sara's partner when she transferred to swing shift, had a habit of asking non-stop questions.
  • Moving Buildings: There was an episode where someone literally stole a house and dumped it in the desert.
  • Ms. Fanservice: Catherine and, briefly, Riley. Wendy might also count.
    • Ronnie, Sara's swing shift partner, in "The Chick Chop Flick Shop."
  • The Murder After: Warrick and a stripper who is found dead in his car.
  • Murder by Mistake: In "The Lost Reindeer", the murderer planned to kill the man hired to play Santa at a Christmas party. However, the Santa left early and one of the other guests put on the costume.
  • Murder by Remote Control Vehicle: In "Boston Brakes", the Victim of the Week is murdered by the use of a computer program that allows the braking and steering systems of a car to be remotely hacked.
  • murder.com: Nick's plight in "Grave Danger" is broadcast live over the Internet.
  • Murder-Suicide: Generally played straight, though it was inverted in one episode where a stalker attempted suicide in his crush's house, resulting in three people dying.
  • Murder Is the Best Solution: The whole franchise is loaded to the gills with people that get a bit too driven with their desire to take out an obstacle (accidentally or not). To provide some examples:
    • "Cats In The Cradle": An eleven-year-old girl being denied one cat from the local Crazy Cat Lady (who doesn't want to part with it, even after the kid points out she has a dozen and it's not as if the cat will be taken far away because they live on the same block) drives the kid to bash the woman's brains in and be completely unapologetic about it.
    • "Who Shot Sherlock?": A member of a Sherlock Holmes LARP fan club gets angry that the club's president and Sherlock Holmes player, out of narcissism and a desire to stop playing, will dissolve the club and refuses to allow anybody to keep it active without him — so she decides to protect the only place where she felt she could escape the tedium of her life by blowing the man's brains out and make it a Holmesian attempt at The Perfect Crime while she's at it.
    • "Caged": A man gets so full of road rage over a woman tossing a cup of coffee at him (in her defense, he started it by nearly hitting her car and then calling her a bitch when she complained) that he chases her several miles and then uses his car to push hers right into the path of an oncoming train.
  • My Card: The investigators will often give a witness their card and say "call me if you remember anything."
  • My Eyes Are Up Here: In "You Kill Me", Greg is looking at Wendy's naked body on the autopsy table. As his gaze starts to wander down her chest, Wendy's eyes snap open to remind him that she died from a neck wound. (It Makes Sense in Context as this is all taking place in a thought experiment of Hodges', and Wendy is not really dead.)
  • Myth Arc:
    • The "Miniature Killer".
    • The Bathtub "Suicides".
    • Dr. Jekyll.
    • Nate Haskell.
  • Mythology Gag: The CSIs investigate the murder of a family in the Season 1 episode "Blood Drops". When another family is slaughtered in Season 6, the episode is titled "Gum Drops".
  • Nausea Dissonance: In one episode, Catherine sends the rookie officer escorting her out because of this trope (she doesn't want vomit contaminating her crime-scene). The suspect turns out to have been hiding, and attacks her.
    • This doubles as a Call-Back when Warrick berates the officer for not clearing the scene because "[They] lost a CSI 2 years ago because of [that]." He's referring to the first episode, in which he was the one to leave another CSI alone at a crime scene.
  • Necro Cam: Done multiple times in every episode.
    • The show is also notable for its gory body-dives, in which the camera flies around inside somebody's body (often tracing the path of a murder weapon), accompanied by all sorts of icky Foley noises. This is commonly referred to as TMI Cam.
  • Need a Hand, or a Handjob?:
    • In an early episode, Sara casually asks Grissom to "tape me up," as part of investigating how a victim was bound with duct tape; Grissom, who was conversing with Catherine, dryly remarks, "I love my job" before heading out.
    • Inverted when Catherine, while being evaluated by Grissom, complains about her lack of social life (and sex). "How can I help?" Grissom asks, and has to clarify that it's not THAT kind of help when Catherine raises her eyebrow at him.
    • Another episode has Sara ask Grissom "Do you want to sleep with me?" Grissom has a Beat of WTF (this is before their Relationship Upgrade, but went along with all the Ship Tease they were having) before she reveals it to be a literal reference to sleep, as Grissom had stated disbelief that she was having nightmares, and she says that he should be there to see her wake up screaming in the middle of the night in order to make him believe her.
  • Never Suicide:
    • Subverted in one episode where an investor shoots himself at a party. It originally looks like a staged suicide since he's still holding the gun, which usually doesn't happen as the muscles relax after death.
    • Another variation: The villain of an early story-arc staged identical suicides of men who were born on his father's birthday, the same date as and manner in which his father was murdered - up to and including a faked recorded suicide note. He did all this to prove his father's murder wasn't a suicide. This was eventually subverted as Millander, who it turns out was born on the same day as his father (and Grissom, incidentally), killed himself in the same way he had killed the other men.
    • Inverted in another episode: a man is found in the woods with all the evidence initially pointing towards murder. It actually turns out to be a suicide designed to look like a murder so his wife would receive his life insurance money.
    • Subverted yet again in another episode, when one man throws himself in front of a car. The entire episode runs like an ordinary investigation, the suicide letter being the final twist revealed only seconds before the episode ends.
      • Ironically, this ended up turning into a murder, as the driver that hit him had been drunk at the time and, rather than admit to hitting someone while intoxicated, hid the still-living man in his garage and tried to dispose of the body the next day.
    • One double subversion, when a Sherlock Holmes impersonator is found shot to death. Like the above example, the episode runs as a murder investigation, until the team discovers the gun tied to an elastic in the chimney, revealing that when the victim shot himself and let go of the gun, the elastic snapped it back into the chimney. Then we find out that the real murderer, in a reference to one of Holmes' later cases, had set the whole thing up to look like a suicide that had been set up to look like a murder, as an appropriately Holmesian mystery. Yes, a murder, made to look like a suicide, made to look like a murder.
    • "Trends With Benefits" starts out looking like the real-life suicide of Tyler Clementi (see Ripped From The Headlines), but it turns out the victim's death was accidental.
  • Never Trust a Trailer:
    • The 300th episode "Frame By Frame'' was promoted as featuring a return guest appearance by Marg Helgenberger, reprising her role as Catherine Willows. Some TV Guide entries even claimed that Catherine returns to assist the CSIs in a cold case. In actuality, Catherine only appears in flashbacks (newly shot, mind you), and the character never actually appears in the present time.
    • The previous episode's trailer had Greg saying he's going to leave the CSI (after he had said in the last episode that, unlike Sara, he'd never tire of the job); actually he's afraid he's going to be forced to leave if it's proven his negligence put an innocent man in jail for a decade (it was actually a rookie cop who unwittingly contaminated the crime scene)
  • Night Swim = Death: Too many episodes to list. It's usually signaled by finding the body floating in the swimming pool.
  • Nice Character, Mean Actor: In-universe and for a Top Chef-esque reality TV star: the show's producer was going out of her way to make him look like a nice underdog because he and another chef were her college buddies — and then she found out they were the ones who raped her sister (I think). She turned him into four fancy dishes and poisoned his buddy with almonds (actual almonds (well, almond powder), not the bitter kind).
  • No Badge? No Problem!: CSI gets Flanderized into this in parodies but it's not as prevalent as it's made out to be. While the CSIs tend to do things that the police would be the ones to do in real life (like interviewing suspects or capturing them, though the latter tends to happen only when someone they plan to just speak to runs away), Grissom often reminds civilians he isn't a cop, and at one point was told to leave the scene by Brass when it became apparent that a suspect was still there.
    • This said, it is quite common for them to enter a possible scene with weapons drawn... ahead of the actual cops.
  • No Celebrities Were Harmed:
    • Season 8's "Two and a Half Deaths" was written by Chuck Lorre and features the murder of Annabelle Fundt (Katey Sagal), a demanding, temperamental sitcom star who is clearly inspired by Lorre's negative experiences writing for Roseanne Barr on her eponymous sitcom and Brett Butler on Grace Under Fire. The Show Within a Show, Annabelle, combines elements of Roseanne (named for its star and features a critically panned plotline in which the working-class main character wins the lottery) and Grace Under Fire (main character is a single mother), and the flashback in which an intoxicated Annabelle offers to show her new breast implants to her horrified onscreen son is based on an incident involving Butler.note  Annabelle's parasitic boyfriend/PA is equally clearly inspired by Barr's ex-husband, Tom Arnold.
    • Hilariously averted in volume 6 of IDW's tie-in comics. The story ends with them carting off Greg Rucka for the attempted murder of Joe Quesada.
  • No Dead Body Poops: Averted in “A Little Murder”, where the smell leads to a Vomiting Cop who runs out of the house and to Catherine getting attacked by a suspect while she’s alone.
  • No Medication for Me: In "Recipe for Murder", a bipolar couple decide to stop taking their lithium together. The man goes completely manic, while the woman seemingly commits suicide. The suicide ultimately turns out to be murder, but one brought about by her decision to stop medicating.
  • No Name Given: The little girl in "Lucky Strike". Her name is never mentioned, even by her own mother when she's complaining about her being left out.
  • No-Sell: Agent Ryan doesn't flinch when a sadistic criminal has a gun to her face, nor does she bat an eye when he slashes her arm with a knife — in fact she suggested he use it instead of the gun because it would be more "his thing" as a sadist (actually she was protecting the cops who were about to bust in, and the slashing added years to his sentence).
  • Non-Actor Vehicle: Justin Bieber guest-starred as anarchist teen bomber Jason McCann in two episodes.
  • Noodle Incident:
    • DB and Finlay's past. Something caused them to become estranged for years. Probably not an affair, seeing as DB's family wants them to get along. Turns out Finlay went to extremes to prove a VIP was guilty and DB was forced to fire her despite believing in her.
    • We never find out exactly what Kelly from "Grave Danger" did to go to prison, or if she's actually innocent as she says. They say she was an accessory to murder along with her boyfriend. Although who the victim was, who her boyfriend was, why he killed him, or how she supposedly helped are never explained. Surprisingly, the Necro Cam bit they do in the same scene only makes it more confusing.
  • "No Peeking!" Request: In "A Little Murder", Catherine gets into a tussle with a suspect who manages to escape. So she decides to take no chances and wants to send all of her clothes as evidence in case there's some trace of him in them, so she asks Warrick to turn around and guard the back of the ambulance as she undresses.
  • Not Proven: If an episode wants a Downer Ending, this is usually the way it goes about.
  • Occam's Razor:
    • In a rather bizarre instance, Grissom brings this up in one episode to suggest that the killer was...the Nazi Mad Scientist Evil Twin of the man they thought was the killer. That was the "simplest explanation" he offered (he was right, of course, but still - hardly "simple").
    • Used also in Catherine's final episode where she's determined to prove a ruthless millionaire killed an old friend of hers as well as an FBI agent and was behind attempts on Catherine's life. She does become confused when she realizes the leads don't seem to be panning out for the guy. It's Sara who cites the trope by noting this all started when Catherine's "old friend" who she hadn't seen in years showed up and told her about her husband being this criminal and then she seemingly vanished in a car fire. As it happens, the "friend" set this whole thing up to trick Catherine into going after her husband to cover up how she'd been using her husband's foundation for her own criminal acts.
  • Offing the Offspring:
    • One woman was so devoted to her son that she used her gangster boyfriend to murder her adult grandchildren and nearly her great-grandchild when she learned her granddaughter had evidence her son had molested them (his children, not the great-grandchild). Her excuse for being able to kill her own family so easily was the fact that she had given birth to and raised her son while the other three may as well have been strangers. Sadly this was ripped from the headlines (and before you ask: yup, Florida).
    • One early episode had a woman simply murder her 7-year old daughter on an amusement park ride to make it look like an accident so she would be free to run off with her boyfriend without having to deal with the responsibility. The ending has it ambiguous if the CSIs have enough to convict her.
    • A B-plot case had woman who murdered her 13-year old daughter because she thought the daughter was hitting on her adult boyfriend.
    • A case of a couple who killed their infant son because he was exhibiting signs of Tay-Sachs disease, a disease which previously took the life of their older son. However, their second son didn't have Tay-Sachs and was exhibiting symptoms due to incidental and accidental gardening chemicals poisoning. His parents killed him by leaving him in the car on a dangerously hot day because they didn't want to go through another experience like that of their first child.
    • The Season 6 episode "Still Life" had a woman who after her soldier husband was killed in action, killed her young son and buried him in the back yard as she couldn't face the idea of her son growing up and going off to war (her husband came from a military family) and getting killed like that. She cut all ties with her husband's family and would post doctored photos of her and another family's son on social media to make it look like her son was still alive. Grissom makes a reference to the Greek character and play Medea after the case is resolved.
  • Off-into-the-Distance Ending: The final episode of the series ends with Grissom and Sara heading out to sea on Grissom's boat.
  • Omniscient Database: Revolutionized this trope. They have demonstrated databases on blood, hair, rope, wire, shoe prints, tire treads, tire rubber compositions, and even clown makeup patterns. There was a Lampshade Hanging in a sixth season episode, in which Hodges sarcastically suggested searching a database to discover the brand of a hot dog.
    • To be fair, the clown makeup database belonged to a clown guild in Las Vegas, which is Truth in Television. Each professional clown is required to wear a unique make-up that is registered in the guild. Wearing another clown's make-up is punishable.
    • An early Season Ten episode features a database on gangs, including cases related to each gang, their territory and their known members.
    • In fact, it's when CSI avoids the trope that it can be jarring. A reoccurring scene is the local trace evidence guy naming a compound, and the CSI identifying the compound's common name, and its uses, including the more arcane (say, Jeweller grinder lubricant) on the top of their head. Said arcane use are always the key to cracking the case. This gets jarring because there ARE databases to identify the most common uses of chemicals.
  • One Steve Limit: Averted with David Hodges and David Phillips.
  • The Only One: The Crime Scene Investigators (and Brass) are the only law enforcement personnel who care about getting the criminals. The DAs only care about getting convictions, even if it is a wrongful one. Judges are at best unhelpful or helpless, at worst are corrupt and seek to hinder the CSIs in any way possible. Other cops just don't care. Parole boards are more focused on bureaucracy than on doing their job of making sure bad people stay in jail. Fire Departments are ridiculed for destroying evidence, and the never-seen day shift CSIs are a bunch of lazy incompetents.
    • For the "other cops" part, subverted quite impressively by part-time Miami character Aaron Jessop, who apparently had the observational and mental skills to be a CSI himself. Pity he tripped a booby trap and got blown up.
  • Once per Episode: DB will mention his wife. Or call her. Or both.
  • Only Known by Initials: D.B. Russell.
  • Open Heart Dentistry: In "Willows in the Wind", Doc Robbins (a pathologist) performs impromptu field surgery on Catherine, cauterising a gunshot wound with a curling iron.
  • Orgy of Evidence: In "The List", the team investigates the murder of an ex-cop who was in prison for murdering his wife. Over the course of the investigation, it becomes apparent that the original case against him was based on an orgy of evidence.
  • Orifice Invasion / Orifice Evacuation / Chest Burster: Rats seem to like getting inside corpses in this show.
  • Our Ghosts Are Different: In one episode, four recently deceased people talk about how they died and what they'd been doing till then. One of the "ghosts" was an Iraq War veteran who just returned home only to be killed trying to stop a robbery. The other three remark that it must have been the saddest day of his life, but the vet said for him it was the happiest, because he got to see his newborn daughter for the first time.
  • Outranking Your Job: Brass spends a surprising amount of time kicking down doors for a police captain. Averted by Ecklie, who rarely investigates a crime scene himself, as befitting his supervisory role.
  • Papa Wolf: The occasional suspect, especially in the case of an Asshole Victim.
    • Grissom also gave Catherine's abusive ex-husband an Oh, Crap! moment when said ex tried to bully Catherine.
    • In fact, Grissom tends to go Papa Wolf whenever his team are at risk of harm, for all he usually comes across as emotionally distant.
    • D.B. now. Do not mess with his family.
    • Ecklie has his moments of this when it comes to Morgan. He's not pleased when he finds out that Morgan testified on Hodges' behalf at a hearing for his possibly-a-Green-Card-scam engagement, and he punches a guy in the face when he won't admit to knowing where a kidnapped Morgan is. As he doesn't really have quite as much of an opportunity to go out and investigate things as the others, when Morgan ends up in danger (as he's the Undersheriff/Sheriff), he doesn't get as much Papa Wolf behavior as the other examples here, but it's still very obvious that you do not want to be around him and be someone who's hurt her.
    • Some of the fathers involved in the cases qualify.
  • Paper-Thin Disguise: By the Diabolical Mastermind in "Living Legend". It's not so much that they don't see through his disguises (after all, he's been missing for 30 years), it's that no one notices that the disguises all look like one another.
  • Paranormal Episode:
    • Had an episode with a psychic helping the CSIs. He died before we could find out if he was a fraud, though all his predictions did come true.
    • "Toe Tags", which had the stories told from the corpses' perspective, like they were ghosts. The cases themselves are normal, though; the supernatural elements are just a framing device.
    • "Go To Hell" in the end leaves up in the air whether or not Amy Macalino was so much of a crazy sociopath that she honestly thought acting possessed by the Devil (complete with struggling through an exorcism) was a good way to create an Insanity Defense for the murder of her parents and younger sister, or if she was actually possessed.
  • The Pen Is Mightier:
    • In "Cat's in the Cradle'', it is discovered that the Victim of the Week was stabbed to death with a glitter pen.
    • In "A La Cart", the Victim of the Week in the B Story is stabbed through the temple with a ballpoint pen while dining in a blacked-out restaurant. The nib of the pin snaps off in the victim's brain, and the leaking ink that would have stained the killer's hand becomes an important clue.
  • The Perfect Crime:
    • In "Working Stiffs", a lowly office drone makes a seemingly perfect get rich quick scheme. He manages to get the unbreachable safe open, but is crushed against the wall by a piece of it that comes flying at him. Upon seeing he actually succeeded in doing the impossible, his last words are "I knew it would work..."
    • Played straight whenever they don't get the perp, though special mention goes to "Alter Boys" (the team knows for sure that the actual killer is not the man arrested but his Evil Twin, yet every bit of evidence points to the former), an ep with one of the most remarkable Downer Endings in the show.
    • Subverted in "The Unusual Suspect" where the crime itself wasn't perfect - but the accused's genius 12 year old sister exploited reasonable doubt and double jeopardy protections to effectively get her brother to be found not guilty, despite the fact that he actually committed the crime. Effectively and literally allowing her brother to get away with murder, by not only confessing to the crime herself on the stand, not only having the means and the motive, but also producing enough evidence that she could've murdered the victim herself.
    • Before both of these was "Organ Grinder", in which the perps were a tag-team of Black Widows who would go from state to state, one of them marrying wealthy men for their money and the other poisoning the husband, with the roles flip-flopping every other kill. They would then meticulously destroy all evidence so that the only thing investigators would have on them would be their own testimony... and then each flip on the other, forcing the authorities to let them go. They end up being the first perps on the show to get away completely scot-free (not counting Millander, who is brought down later on). In an interview, the episode's writer said she realized this was a huge Anticlimax, and if she had the chance to write it again she would've had one kill the other and go down for it.
  • Perp Walk: Almost at least Once an Episode.
  • Pet the Dog: A posthumous one for Millander, as his son has only happy memories of his father, especially of his father's (though he didn't know it at the time) special effects shop.
  • Piranha Problem: In "Table Stakes", the killer disposes of a body by feeding it to piranhas.
  • The Plague: In "Bad Blood", the Victim of the Week was suffering from a hemorrhagic fever before being shot. The virus had been stolen from a local lab. Greg and Sarah are exposed to the blood while processing the scene and are quarantined while the rest of the team races to prevent further outbreak. However, at the episode's end, it is revealed the pathogen had become inactive by the time they processed the crime scene.
  • Plague of Good Fortune: A weird example on one episode ("Better Off Dead"), where a suicidal man (who entered a suicide pact with a bipolar woman and unwillingly drove her to suicide by accidentally poisoning her dog while he was trying to kill himself) tries to kill himself throughout the whole episode but anything he tries is stopped by incredible luck (like standing still in the middle of a shootout and being the only person not to be hit or trying to jump off a building but being yanked back to safety by a friend of the woman that had been searching for him in order to get revenge).
  • Plucky Comic Relief: Greg Sanders before entering the field is an excellent example of this trope. The lab rats in his wake took up the mantle.
  • Police Are Useless: A major wallbanger happens in Season 11's "Cello and Goodbye". Ray catches up to Nate Haskell at a carnival, both men have guns drawn. Haskell is raving about how Ray's ex-wife is still alive, wielding his gun all over, yelling at the top of his lungs, and just seven feet away. Cops catch up to Ray and... arrest Ray. They somehow miss the screaming madman on a nearby platform with a big gun.
  • Poorly Disguised Pilot:
    • CSI did this with "Cross-Jurisdictions" to launch CSI: Miami, which in turn launched CSI: NY.
    • And the episode "Hollywood Brass" certainly feels like a PDP. Were they thinking about a Jim Brass spin-off set in LA?
    • The episode "Kitty" definitely felt like a pilot...and it was ordered to series as CSI: Cyber.
  • The Professor: Ray Langston was teaching college before he joined the team.
  • Pro Wrestling Episode: In "Mascara", one of Ray's former students is murdered and the investigation plunges the team into the mysterious world of Mexican wrestling.
  • Put on a Bus: Inevitably for such a long-running series, this has happened several times.
    • Sara and Grissom, presumed retired for good, although Grissom did have a cameo in Season 11's "The Two Mrs.Grissoms". Sara returned for a few episodes starting in Season 10, and began Commuting on a Bus starting in Season 11.
    • Catherine as of Season 12.
    • Wendy (Liz Vassey) got on the bus in Season 11.
    • Sofia and Riley also make quick exits even after getting promoted to the titles.
  • Quip to Black: The CSI examples are famous.
    • Grissom started the trend, but, to be fair, it was CSI: Miami that took it to a (much cheesier) new level.
    • Averted in one early episode where Grissom makes a quip, the musical cue for the fade happens, but is suddenly interrupted by Grissom's cell phone, informing him of another case to handle. At that case's location, he makes another quip with the cue, and his phone rings again. At this third crime scene, Grissom doesn't even bother making a quip, and the show fades into the theme.
  • Rabid Cop: Example of In-Universe Flanderization on the episode "You Kill Me": the experimental tabletop game "Lab Rats" has Brass as a character, and Game!Brass has an affinity for nonchalantly applying violence during interrogation and to anybody who resists arrest (shooting Bobby Dawson and then making a Pistol Pose).
  • Race Against the Clock:
    • In "Invisible Evidence", a judge throws out all of the evidence against an accused rapist-murderer because a search warrant was not obtained to search the car where the evidence was found. Gil gets a 24 hour continuance for the team to gather new evidence.
    • Another episode has the team trying to prove a violent felon's guilt when the detective who arrested him is alleged to have been a Rabid Cop who forced him to confess, and the court is set to overturn the conviction. The team ends up not being able to definitely prove the case in question, and the rest of the episode focuses on trying to keep the felon from being released by tying him to another unsolved murder, despite the team having previously said they needed to make the first case rock-solid because of all the other potential appeals if the felon's allegation gets upheld.
  • Racing the Train: "Caged" opens with the Victim of the Week trying race a train to a level crossing in an attempt to stage a Train Escape to get away from the vehicle that is chasing her. Realising she is not going to make it, she slams on her brakes, only for the vehicle behind to ram her and force her into the train.
  • A Rare Sentence: In "You've Got Male", Grissom discovers that the killer had taken water from a farmer's irrigation tank, leading to this exchange:
    Grissom: Can I fingerprint your spigot?
    Farmer: No one's ever asked me that before.
  • The Rashomon: Rashomama where the truck full of evidence was stolen by a suspect's boyfriend, leaving the team to construct a case using only their memory. Four members recount their experiences.
  • Real Men Get Shot: Brass and his "injury date" tattoos.
  • "The Reason You Suck" Speech: All three series have their fair share of these, but Catherine is the subject of a brutal one from Leo Finley at the end of "A Thousand Days on Earth". Even though he's innocent of murder, Leo's fiancé Norah now knows he's a sex offender (which he only became by accident — he obliviously stripped naked in front of a group of kids while he was high) because Catherine dug up his past during her investigation. He tells Catherine that Norah kicked him out of his own home and got a restraining order, in addition to telling all their neighbors as well as his boss, resulting in him becoming a social pariah and getting fired from his job. And it's all Catherine's fault. You can feel Leo's pain as he calls Catherine a "blonde Nazi bitch" and screams at her for not caring about ruining his life. All she can do is pathetically try to justify what she did by saying she was only doing her job, then she threatens to shoot him when he doesn't calm down. Leo just tells her in a chillingly calm tone not to bother since he's already thinking about killing himself and that if he does, he's going to find out where Catherine lives and shoot himself in her front yard.
  • Reckless Gun Usage: Nick Stokes investigates how a woman got shot with no evidence of a shooter anywhere near. The answer is that there was an idiot who had a gun and made a shooting range in the backyard, in the suburbs within city limits, a big-time city ordinance no-no, and a stray bullet went into the air and struck the woman on the decline. When they arrest him, he protests it was an accident and Stokes contemptuously responds "Well, that's why it's illegal to shoot guns within city limits, genius!"
  • Rasputinian Death: The episode "Ending Happy" - played for comedy!
  • Real Song Theme Tune: "Who Are You", by The Who.
  • Redemption Equals Death: Keppler killed an innocent man on the word of a corrupt cop. Guess what happens in the episode that outs the secret?
  • Regularly Scheduled Evil: Serial-killing dentist Doctor Dave (played with chilling effect by the great Ned Beatty) started killing when he was in his late teens, and only got "the urge" every ten years or so. He doesn't get caught until he's in his seventies. The length of time between murders is one reason it took so long for the police to catch him.
  • The Reliable One: Back in the days before he was promoted to the main cast, DNA specialist Greg Sanders was this. Once he became a featured player, this position was taken up by David Hodges, much to the surprise of everyone.
  • Revolving Door Casting: Seems to slowly be heading towards this with the original cast gradually leaving the show and replacements being brought in over time. note 
  • Ripped from the Headlines:
    • "Unfriendly Skies", inspired by the Jonathan Burton case and aired only months after the incident.
    • "Anatomy of a Lye", based on the Gregory Biggs case.
    • "After the Show", an almost word for word retelling of the Linda Sobek murder, and specially notable for having been co-written by Elizabeth Devine, a former CSI involved in the original case who is now a consultant to the show.
    • "Trends With Benefits" is based on the suicide of Tyler Clementi who was outed by his roommate with his webcam, with a twist: The gay college student's death was an accident, him being gay wasn't an issue, and he was the one who was using hidden cameras (he wanted to be the next Perez Hilton), in this case to expose his professor raping a student.
    • "Burked", based on the Binion murder case. While the key story elements are there, the identities of the killers are different.
    • The episode where a rich guy hires his girlfriend and his girlfriend's jealous ex-boyfriend to stage a carjack in which his wife is killed, only to be killed himself right after by that ex-boyfriend, is closely modeled on this 2000 crime case. The show upped it by having the girlfriend also die in an accident and the killer trying to pass himself as a good Samaritan.
    • "Empty Eyes" bears many similarities to Richard Speck's crimes.
    • The main suspect in "Bittersweet" is closely modeled on Karla Homolka.
    • “Pledging Mr. Johnson” was somewhat based on the real life death of a medical student in the 60s from a similar liver-swallowing fraternity hazing.
    • The “rebirthing” therapy case was based on the Candice Newmaker case, in which Candice was forced to go through rebirthing therapy by her adoptive mother, leading to her death.
  • Rising Water, Rising Tension:
    • In "Lady Heather's Box", Lindsey is trapped in a wrecked car in slowly rising flood waters and Catherine has to race to locate and rescue her.
    • Part two of Sara Sidle's Tension Conga Line at the hands of the miniature killer in "Living Doll"/"Dead Doll" Left abandoned in the desert, with her arm pinned under an overturned car, she's first threatened by a Coyote which takes a keen interest in her exposed arm, before being chased away by an impending storm - which results in a flash flood, causing this. Only for Sara to escape the car (thanks to the flood shifting the vehicle's weight and freeing her arm), resulting in her being lost in the desert, and almost dying from heatstroke/dehydration. All the while, the CSIs and police are desperately trying to find her.
  • Road Sign Reversal: A variation in "Anatomy of a Lye". A man deliberately alters the trail map his fiancee is using so she will not beat his time on a particular trail run. However, his alteration causes her to be trapped in the mountains during a flash flood and she drowns.
  • Rogue Juror:
    • One episode of has the holdout on a jury found dead. The suspicion is that he was murdered to end the deadlock (on top of being an incredibly belligerent jackass), when in truth he was stung by a bee that had flown into the jury room through an open window and died from a massive allergic reaction.
    • The post-"Fannysmackin'" arc regarding Greg's Accidental Murder of Demitrius James in the defense of a man he and a mob were beating up has Sanders trying to defend himself in court and, overall, what looked like an open-and-shut case (Greg saw the crowd, he tried to scare them off with his car, James tried to attack instead, he hit him with the car because he couldn't brake in time, it's all clear) turns into a circus of accusing Greg of alleged Police Brutality, racism and even the possibility of having been a Drunk Driver during the act (thus ending with the James family forming Irrational Hatred for cops in general and Greg in specific) because of a jackass juror that wishes "all of the facts being brought to light" and won't vote until he hears them (even interrupting testimonies to question the witnesses).
  • Rule-Abiding Rebel: Investigating a death during a high-stakes poker game, the heroes discover that the waitress put eyedrops in the victim's drink as payback for him being a lousy tipper. She'd meant to give him diarrhea and force him to leave the game early, but he died before they kicked in.
  • Running Gag: Mentioned by name by Hodges in "You Kill Me".

    S-Z 
  • Sacrificial Lamb: The series began with a Naïve Newcomer character who basically served to introduce the various members of the show's cast. With that out of the way, she caught two in the back of the head, turning into the second victim and confirming her status as the New Meat.
  • Sarcasm Failure: When Grissom doesn't do the Quip to Black.
  • Sand Necktie: Happens to the Victim of the Week in "Jackpot". He is buried up to his shoulders in a hole in the forest, and then his neck and face is cut so he will bleed and attract predators. His head eventually becomes detached from his body.
  • Scaramanga Special: "All In" features a large decorative belt buckle that is actually a functional .22 derringer. The original owner, a collectibles dealer, wore it as a hold-out gun.
  • Scary Black Man: Several of these have been suspects over the years.
    • An amusing subversion came from a black teenage gangbanger and Smug Snake, who tried to use this trope to intimidate Warrick. Warrick, of course, wasn't the least bit impressed.
    • Dr. Langston when he's been sufficiently provoked. The look on his face right before he murders Nate Haskell all but cements it.
  • Science Hero: Grissom and, later, Ray.
    • Most of the CSIs, really. Rather than bringing in criminals, they catch them using various forms of forensic analysis (blood spatter, facial reconstruction, DNA matching, etc).
  • Second-Face Smoke: In "Hog Heaven", a biker blows smoke in the face of one of the gang's bitches (who is actually an undercover cop).
  • The Secret of Long Pork Pies: In "Appendicitement", the owner of a BBQ restaurant was killed by his wife and the cook, who then disposed of the body by cooking it up and serving it to the customers. The flashback implies it was very popular...up until the BBQ had to close because of an outbreak (courtesy of said meat).
  • Serial Killer: The Miniature Killer, Doctor Jekyll, the Blue Paint Killer.
    • Season 1 alone had three: Paul Milander, the I-15 Killer and the Strip Strangler.
  • Serial Killer Baiting:
    • In "Strip Strangler," the CSI team are hunting the titular villain, who would rape and then strangle his victims to death and target tall, female brunettes. Sara offers to act as bait to draw him out as she matches his victim preference.
    • In "Skin in the Game," Morgan goes undercover as a prostitute trying to find a serial killer. However this goes horribly wrong as Morgan is abducted.
  • Serial Killings, Specific Target:
    • In one episode, a comedian dies from drinking a poisoned bottle of water. Then a kid dies from drinking the same brand. The first victim was the target; the killer (a rival comedian who hated his style) says he blames the CSIs for not finding the poisoned bottle in time as he's arrested after confessing out of remorse.
    • Doctor Jekyll, when finally caught after a season-long killing spree, was in the process of murdering the true object of his rage- his own father. Played with in that every victim was connected to the main target, friends and acquaintances that they admired, so every murder was designed to make them suffer before they died, as well as giving Jekyll a chance to take out his frustrations on somebody.
    • Done with a serial rapist in "Helpless", where it turns out that his first two rapes were 'dress rehearsals' so he could have all of the details worked out by the time he went for his intended victim.
  • Series Continuity Error:
    • Sara says in one ep she has a brother, then in season 12, she says she was an only child.
    • Sort of with the original bios on the CBS website. Catherine was said to have been born in Bozeman, Montana (likely recycled to CSI: NY's Lindsay) and Grissom's father was said to have been involved in smuggling. The first guidebook, covering the first three seasons, has this information as well.
  • Serious Business: Among others, the Furry Fandom, Scrabble, eating contests, vampires vs. werewolves, LARPing, and Robot Rumble!
  • Sex Is Evil: One of the more frequent knocks on CSI is that this is pretty much how it treats any sex practices (regardless of consent) outside of hetero and committed.
    • This is a common problem with any Crime and Punishment Series, really, as the only time the characters usually encounter alternative lifestyles is when there's a grisly murder involved.
      Rule 34a: There's also a CSI episode about it - no exceptions.
    • CSI tends to be a bit schizophrenic about this, really. While they tend to portray "perverts" of various types as being twisted in various way aside from their sexual appetites, those that weren't involved in the crime of the week, and even some who were, are ultimately portrayed sympathetically for the most part. The best example is Recurrer Lady Heather, a dominatrix who is a tragic and sympathetic character. Admittedly, most of the tragic part is in some way due to her lifestyle, but it is ultimately left up to the viewer to decide whether this is due to her own "sins," or other people's (including her own daughter) reaction to them.
    • Humorously, ex-stripper Catherine seems to be the most squicked out by alternative sexual practices. Grissom, of course, finds it all very fascinating.
    • Toyed with in an early episode where Nick sleeps with a woman who is found dead the next morning. As the last person to see her alive, he is automatically the prime suspect in the investigation. Turns out, she was a prostitute who was going to go solo, and her former pimp killed her after Nick left her house.
  • Sexy Santa Dress: A variant occurs in "The Lost Reindeer", when the office party animal arranges for a stripper dressed as a sexy reindeer to perform at the office Christmas party.
  • Sexy Whatever Outfit: In "The Lost Reindeer", the office party animal arranges for a stripper dressed as a sexy reindeer to perform at the office Christmas party. Overlaps with Sexy Santa Dress, at least thematically.
  • Shameful Source of Knowledge: Inverted in an episode which is set over the course of a year. A junkie who Nick helps out at the beginning (and slowly sorts himself out over the course of the episode) recognises the smell of some drugs the murderer poisoned the victim with. However, he isn't willing to reveal what he knows until after he's gone clean, since he didn't think he'd be believed.
  • Ship Sinking: Turns out Grissom and Sara's very, very, very long-distance relationship was too hard, though it appears they’re back together as of the series' end. Also Sara's potential romance with a hook-up: not only was he murdered by the stalker from the diner massacre episode, the stalker taunts her with the fact he had to pay him to see her again.
  • Ship Tease: Grissom and Catherine playfully flirt with each other and it never goes anywhere. To wit:
    Catherine to Grissom: (while helping the latter put on a tie) You need a woman.
    • Grissom, when Catherine returns from Miami in which she helped investigate a case there, "I missed your tush".
    • The "How can I help?" scene (see above for details).
    • There have also been hints towards possible Nick and Sara - Word of God states that Sara's phonecall at the end of "You've Got Male" was originally intended to be to Nick, and they have had moments of reciprocated flirting. Likewise, Catherine and Warrick, to the point where Catherine is upset to learn of Warrick's marriage and even outright comments on losing the dream.
    • Grissom and Heather could also fall under this as it is never outright confirmed that anything happened between them. Heavily implied, yes, but always in a way that, taking Grissom as being Grissom, could have a perfectly innocent explanation.
    • There were hints here and there for Greg and Sara as well, especially during her time mentoring him in the fifth season. A notable example comes from the episode "4x4":
      Greg: Sara, I just want you to know that when we were in the shower, I didn't see anything.
      Sara: Really? Gosh, I saw everything.
    • Grissom and Sara themselves in the first season.
      Sara: Do you want to sleep with me?
      Gil: ...Did you just say what I think you said?
      • Although that was a Rule of Drama moment, as Sara was setting him up for her rationale for taking their current case personally: that if they slept together, then he would know how serious her nightmares were regarding the victim.
  • Shipper on Deck:
    • DB seems to ship Morgan/Greg, seeing as how he's called Greg her boyfriend on at least one occasion.
    • Catherine is one for Grissom and Sara, possibly even before they get together, as she watches approvingly as he orders a plant for Sara to apologise to her.
  • Shoot Him! He Has a... Wallet!: At the end of "The Fallen", a surrendering hostage-taker is shot by the SWAT team when he reaches inside his jacket for his St. Christopher medallion.
  • Shoot the Shaggy Dog:
    • " Fracked", essentially. Just when the team think they've figured out what's going on Ecklie randomly forces them to close the investigation for no real reason. Particularly infuriating because the team have been allowed to proceed with investigations in which they had much less evidence than this one.
    • "A Thousand Days On Earth" is another rather gutting example. Turns out there wasn't even any murder - the dead little girl had accidentally suffocated while playing with her foster siblings. Her foster father, a genuinely repentant ex-con, covered up her death because he didn't want to go back to jail, but before this is found out, his innocent wife is accidentally shot by an overzealous SWAT marksman. As if that weren't bad enough, Catherine unintentionally ruins the life of the totally-blameless first suspect by outing him as a registered sex offender (which he'd only become by accident - he obliviously stripped naked in front of a group of children while high), and in the episode's final scene he confronts her in the parking garage and tells her point blank that someday when she least expects it, he's planning to come to her house and commit suicide on her front lawn.
  • Shot to the Heart: Doc Robbins does this in one episode, where a guy revives on his table.
  • Shout-Out: In "The Grave Shift", Hodges and Langston do a very-thinly-disguised MythBusters-style experiment, complete with Plexiglas shield. All they needed was the "3, 2, 1!" part. There is also the experiment conducted by Nick and company with a ballistics gel dummy in "Who Shot Sherlock?".
  • Shovel Strike: The Victim of the Week in the B plot in "Turn of the Screws" is a 13-year-old girl who gets hit with shovel. The blade severs her spinal column, causing her to asphyxiate.
  • The Show Goes Hollywood: "Hollywood Brass" and "Two and a Half Deaths".
  • Show Within a Show:
    • 48 Hour Mystery, a True Crime show and a homage of CBS's own 48 Hours, have episodes such as "I-15 Killer" and "The Firefighter Imposter", referencing "true" crimes shown in previous episodes of CSI.
    • Astro Quest is pretty much a homage of Star Trek: The Original Series, with Vellikons standing in for Klingons, fans being called "Questers" instead of "Trekkies", with CBS as the distributor to boot. Hodges and Simms are massive fans of the show, with a Dream Sequence depicting him as the Kirk expy to Simms' Uhura, Shahna, and Vina expies. The show is also undergoing a poorly received Darker and Edgier reboot, a reference to Battlestar Galactica (2003).
  • Shown Their Work:
    • More often than you think; it's the editing that turns it into Hollywood Science. All the equipment in the CSI lab is fully operational.
    • There's also the episode "A Space Oddity" involving a not!Star Trek convention, which is filled with references, including the Picard Maneuver. The shirt-tugging one. Since both Star Trek and CSI are Paramount properties, the writers (who also worked on Star Trek: Deep Space Nine) got away with lots of Affectionate Parodies of Trek tropes.
    • Also, assistant coroner Dave Phillips is played by David Berman, who worked as a coroner for a time in real life, and is also a consultant on the show.
  • Shut Up, Hannibal!: Langston had several moments like this with Nate Haskell.
  • Sick Episode: "Grissom's Divine Comedy." Gil is called into work while home with the flu, Nick coughs on Hodges (much to his dismay), and Greg appears to be coming down with a cold as well.
  • Side Bet:
    • In one episode, Greg Sanders' replacement eventually cracks from the pressure to be just like Greg and quits. Nick forks over a bill to Warrick. (Who really shouldn't have been participating...)
    • There's also been a whole episode with a Running Gag about Nick and Warrick having a bet on what happened to the Vic of the Week. Either Warrick can engage in "fun" bets with a buddy without a problem, or, considering this was one of the earlier seasons, the writers were letting their sometimes schizophrenic approach to characterisation show.
    • Another episode sees Catherine and Grissom make a bet over whether two murder victims' deaths were related or not (they were long lost twins). In the end it turns out they were both right, and Catherine rips a bill apart, handing half of it to Gil. This comes after a very heavy conversation, lending to a tension breaker when Grissom reminds her that doing so is a federal offense.
  • Silver Bullet: In "Werewolves", the Victim of the Week is a man suffering from hypertrichosis (an abnormal amount of hair growth over the body) who is shot dead with a silver bullet.
  • Sinister Shiv: One episode featured a shanking in a juvenile detention facility with a shiv made from a razorblade melted into the handle of a toothbrush.
  • Skinny Dipping: "Fracked" opens with three teenagers skinny dipping in a hot spring. They discover a dead body floating in it.
  • Skyscraper Messages: An episode had a businessman do this to try and win back his former fiancee. He rejected her in favour of his boss' daughter. Then changed his mind and invoked this trope. She turned him down (albeit quite gently) but his boss (who was watching from that very building) killed him for rejecting his daughter.
  • Slasher Smile: Rylan Gauss in "418 / 427".
  • Sleeping with the Boss: Grissom and Sara, although much has changed since he left and she left, then returned.
  • Snuff Film: "Snuff". The CSIs investigate a snuff film that was anonymously sent to a pornographic film developer and featured the murder of a young woman
  • Spectator Casualty: In Coming of Rage, a man reflexively fired a handgun into the air and accidentally killed a woman who lived miles away. Sadly, it was probably inspired by one of a number of cases in Real Life where people carelessly firing off guns in celebration have killed innocent bystanders.
  • Sphere Factor: "Helpless" opens with a giant hamster ball rolling down the street and into a couple’s front yard. Zach Fisk is dead inside, and the CSIs are able to trace the path of the ball back to his home. Fisk was interested in claustrophilia, the desire to be trapped in confined spaces.
  • The Spock: Grissom.
  • Spontaneous Human Combustion: One episode has a subplot dedicated to SHC. After finding a charred corpse with all the hallmarks of Real Life SHC cases, Warrick and Sara conducted an experiment. They wrapped a pig's corpse in a cotton nightgown like the woman was wearing, put the corpse on an identical lounger to the victim, and tossed a lit cigarette on it, thereby replicating the scene that they found. Grissom, who already knew about the Wick Effect, congratulated them on a successful experiment, then told them they had to clean up the mess.
  • Stab the Salad: Used in The Teaser of "Dead of the Class". David takes a knife from the block in his kitchen and slowly and menacingly walks into the bedroom to where his very pregnant wife is lying down. He asks her "Why must you force me to do this?" in a suitably menacing tone ... then proceeds to use the knife to cut the tags off a new dress shirt. They were talking about him having to go to his high school reunion without her because she's too tired to stand.
  • Stage Magician: The Amazing Zephyr from "Abra-cadaver".
  • "Strangers on a Train"-Plot Murder: Discussed breifly in S 3 Ep 19 "A Night at the Movies".
  • Strapped to a Bomb:
    • This is the MO of the Big Bad in "Immortality": brainwashing his targets (former clients of Lady Heather), strapping them into explosive vests, and sending them into public areas to blow themselves up.
  • Streetwalker: The first season has Nick falling for the hooker, Kristy Hopkins, who is indeed killed by her pimp. According to her pimp she lied about wanting to get out of it.
    • Something similar happens to Warrick in the eighth season, where he was framed for the young lady's murder.
    • Catherine Willows could be considered this, as she is a former stripper. She hasn't been killed, but constantly faces people and places from her dubious past.
    • Likewise, Grissom's one-time potential love interest Lady Heather could be considered this as she was an intelligent but intense woman who ran an S&M club. She, however, was not the delicate flower in need of nurturing but more of an iron fist in a velvet glove.
  • Spanner in the Works: Several criminals are apprehended when other people unwittingly discover their victims' bodies or provide evidence that allow the CSIs to catch them. Children who get chemical burns from the lye used to try and dissolve a buried corpse, panicking teenage girls who steal a car containing a severed head before the killer has a chance to bury it (see Dead Man's Chest above), one of the same girls slapping her hand on a murderer's car and leaving a handprint that proves the killer was there at the time of the murder, or a Heroic Bystander catching The Peeping Tom who also turns out to be a serial rapist, have all given the CSIs invaluable help over the years.
  • Stolen By Standing Still: In "Suckers", Grissom deduces that the antique katana stolen from a display room in a casino never actually left the room but was stashed by the thief in the ceiling crawlspace. While he is correct, this turns out to be just part of a much bigger con.
  • Strapped to an Operating Table: In "Lying Down With Dogs", the Victim of the Week was strapped to an operating table in a rescue kennel before being injected with euthanizing solution.
  • Subculture of the Week: To name a few...
    • Claustrophilia - see Sphere Factor above.
    • S & M / Dominance - all of Lady Heather's episodes.
    • Vampires & Werewolves were enemies in one episode that had a sort of a Romeo & Juliet twist.
    • The much-maligned treatment of Furries in "Fur and Loathing."
  • Sub-Par Supremacist: The Body of the Week on one episode was part of a small white supremacist gang at his high school. The others are brought in for questioning after being found huffing spray paint in a park, and one misspells a written note asking for an attorney—prompting Greg to wisecrack later that "they've all 'layered' up."
  • Suicide by Cop: In "Crime After Crime", Dirty Cop Sam Vega is caught drowning someone. Despite being surrounded by cops pointing their weapons at him, he draws his pistol and is promptly gunned down.
  • Suicide Is Shameful: In the episode "Who Shot Sherlock?", Greg cites the possibility that a relative of the deceased covered up a suicide as a possible explanation for contradictory evidence at the crime scene. In an odd twist it turns out to be a murder staged to look like a suicide which was staged to look like a murder because of this trope.
  • Suicide, Not Murder: Hodges' 'death' (actually a scenario for his board game) in "You Kill Me" turns out to be this.
  • Suicide Pact: In "Forever", a pair of formally dressed teens are found dead in the middle of the desert. This turns out to have been a suicide pact, although a third party was involved with strong motivation to see both of them dead.
  • Super-Deformed: The CSI: Crime City Facebook Game, where you play a new member to the Las Vegas CSI lab, and must not just search for evidence, but also process it to apprehend the killer of each case.
  • Suspiciously Clean Criminal Record: On one episode, the two suspects in a killing are found with one having killed the other. Brass is surprised at this as the suspect who killed the other has no criminal record. He emphasizes this during the interrogation by showing him a folder of his past crimes. It's empty.
  • Suspiciously Similar Substitute: Dr. Raymond Langston (played by Laurence Fishburne) replaces Grissom in Season 9, though not in terms of position. Riley takes Sara's place.
    • Ray Zig Zags the trope. Being the new guy, he's not the Team Dad that Grissom was, but does take over Grissom's role of the older, sheltered, quiet, intellectual guy.
    • DB Russell plays it a bit straighter. He's quirky like Grissom, has the Team Dad element about him, and has some of the sense of humor at times.
  • Swallow the Key: In "Abra-Cadaver," the killer, a Stage Magician who was perfectly willing to kill his family members for the sake of illusions, does this at the end (although Grissom did think to check his mouth).
  • Symbolic Blood: In "Helpless", a shot cuts from blood that is staining the inside of a human hamster ball that is rolling out of control to red wine that is being swirled around a large wineglass.
  • Sympathetic Murderer:
    • Played absolutely straight in one episode with a guy who is responsible, by complete and total accident, for the death of his grandmother, wife, and next door neighbor, and winds up buried up to his waist in cement for it. The whole thing reads like an extended version of The Far Side, complete with the wife wearing cats-eye glasses.
    • Then there was the guy from "Lying Down With Dogs" who was an FBI agent undercover in a dogfighting ring who could never get enough evidence to prove what was really going on, and was thus forced to watch innocent animals being abused in every way imaginable without being able to do anything, eventually snapping and killing the head of the ring by subjecting her to every torture she put the dogs through.
    • Quite possibly Ray, who seems to have killed Nate Haskell by dropping him from the second story of his (Nate's) house after tying him up. Justified in that Nate is a serial killer who murdered Ray's ex-wife's husband and tortured her for days. Either way Ray's not returning next season.
    • One killer was a genuinely reformed ex-con who became involved in a love triangle with two sisters after being released from prison. The older sister kills the younger accidentally in a fight over him, then smugly points out to the ex-con that if the cops start asking questions she'll just say he did it and send him back to jail. He kills her in the heat of the moment, and ironically does end up going back to jail.
  • Take a Third Option: In the first season, Warrick and Catherine catch a teenage boy who accidentally ran over a little girl. Warrick gives the remorseful kid his number, and tells him to call if he runs into any problems in juvie. In the next season, the kid witnesses a teenage gangbanger murdering his rival. The DA wants the kid to testify, and threatens to extend his sentence if he refuses. On the other hand, the kid knows if he does that the other inmates will kill him. Instead, he calls Warrick for help. Warrick's investigation finds enough evidence to convict the gangbanger without the kid needing to testify.
  • Team Mom: Catherine for a long time... now Sara's kind of getting into it.
  • Television Geography: The frequent presence of lush greenery and vegetation, and moderately frequent rain, in desert Las Vegas on CSI (filming in LA, also a desert but heavily watered) is often a source of amused derision by show fans. Also, Geoff Duncan has written two articles on the geographical inaccuracy of two outside jobs, one in "Jackpot" and another in the 2004 season premiere.
  • Ten Paces and Turn: Played straight in "Way to Go"... except one of the duelists thought it was a joke, and the one that had set the whole thing up was taking his hobby (American Civil War recreation) a little too seriously.
  • Themed Aliases: In "Living Legend", the killer uses aliases that are the names of movie serial killers: Michael Myers, Pamela Voorhess and F. Krueger.
  • Theme Serial Killer: The killer in the two-parter "Skin in the Game/The Devil and D.B. Russell" uses Dante's nine circles of Hell as their theme.
  • There Are No Coincidences: Gil Grissom repeatedly says that he does not believe in coincidences. He even quoted Goldfinger at one point, saying "Once is happenstance. Twice is coincidence. Three times is enemy's action." However, in the episode "Chaos Theory", Grissom is forced, at the end of the episode's investigation, to accept that the death and disappearance of college student Paige Rycoff was the result of a series of unfortunate random events that, when taken in sequence, were only connected because, together, they directly led to the girl dying in a tragic accident that merely appeared at first blush, to be murder. Unlike Grissom, her parents refuse the outcome and still believe at episode's end she had to have been murdered.
  • This Bear Was Framed: In one episode, a woman (who was eating human organs to fight off a rare disease) used dogs to attack her victims, so that the deaths at first simply looked like dog attacks.
  • Thriller on the Express: "73 Seconds" is this trope in miniature, as the team investigate a murder that took place on a tram moving between two casinos; with the entire journey taking 73 seconds, so the killer had to be in the car.
  • Time-Delayed Death: Several examples:
    • A man who was punched in the back of the head in a bar fight and later died of a brain hemorrhage in the bath.
    • A boy who was stabbed trying to prevent his little brother from murdering their mother's boyfriend tries to walk home, but collapses and dies... right under the tires of a cab. The cabbie then gets beaten to death by a mob who thinks he ran the boy down and was about to drive off, when he was actually going for his radio.
    • This was the killer, Dr. Jekyll's pattern, he would knock them out and perform surgery on them that would sabotage their body from the inside, thus causing them to die weeks after the incident without them knowing why.
    • A football coach is savagely beaten about the head while he sleeps; the next morning he wakes up, brushes his teeth, has breakfast and gets the paper while bleeding profusely from his head and mouth. The ME concludes that parts of his brain were just intact enough for him to "zombie-walk" through his morning rituals.
    • A miner gets a long wooden stake stuck on the top of his head and manages to drive from a mine in the mountains to a casino parking lot before he collapses and dies in front of a police officer. The cop is understandably confused.
  • Token Minority: Warrick Brown until 2008. This role was then played by Dr. Raymond Langston (Lawrence Fishburne). After 2011, there wasn't one.
  • Too Dumb to Live: Many examples, but a prime one would be a group of teenage boys deciding to play a ramped up version of Russian Roulette using a mini Uzi. The fact only one boy was killed and no one else was hurt at all is a miracle.
  • Toplessness from the Back: In "Skin in the Game," Morgan goes undercover as a hooker. She has to disrobe to keep her cover intact, and the audience is treated to shot of her unclad back.
  • Train Escape: In "Who and What," it appears the killer has done this. However, he has really paid a hobo to put on his cap and board the train to throw the police off his trail.
  • Trapped in a Sinking Car: In "Bloodsport," one Victim of the Week is a woman who is trapped in a sinking car by a jammed seatbelt, and who drowns after she accidentally shoots a man who is attempting to rescue her.
  • Troubling Unchildlike Behavior: In "Cat's in the Cradle," an eight year old girl murders her Crazy Cat Lady neighbour to gain possession of a kitten, and then attempts to frame her mother for the crime.
  • Trojan Ambulance: In "Malice in Wonderland" it turns out one of the wedding robbers is an EMT who uses his job to learn every road in their city and use that knowledge for speedy getaways. At the end of the episode, he takes David Hodges and his mother hostage in his own ambulance.
  • True Love Is Boring: Grissom and Sidle. After years of UST, their separation just comes somewhat out of left field.
    • Ultimately averted, as they get back together in the movie that wraps up the show, and literally sail off into the sunset together.
  • Trust Me, I'm an X: From "The Theory of Everything":
    Hodges: Trust me, I'm an expert.
  • Two-Faced: In ""The Chick Chop Flick Shop", one of the suspects is a Stalker with a Crush who used to work as a stage hand at the studio where the actress was murdered, until a malfunctioning prop set the right side of his body alight: gnarling his right hand and turning the right side of his face into a mass of scar tissue.
  • Two Lines, No Waiting: Nearly every single episode for most of the run. Occasionally the characters will find out halfway through the episode that the crimes they are investigating are tied together. Some episodes pull this off better than others.
    • There have been less of them recently for budget reasons - you essentially have to hire twice the guest cast.
  • Ugly Guy, Hot Wife: Brutally, brutally played with on the Three Shorts episode "Toe Tags." Turns out that the "hot wife" had depression (but no info is given if it was in response to the marriage or not) while the "ugly guy"... well, he pushed his wife off a cliff, stomped down on her fingers hard enough to break bone when she managed to hold on to the ledge (while giving a nice big Slasher Smile to the camera she was carrying and unknown to him captured everything), and then tried to convince the police that she had committed suicide because she was fed up with him, finally giving a Motive Rant that his life had become hell ever since he married her once he's caught, supposedly because of this trope.
  • Underside Ride: In "XX," a woman tries to escape from a prison in this way and suffers Ludicrous Gibs from getting caught in the moving parts. Subverted when we find out that she was already dead - the killer was getting rid of the body.
  • Unwanted Rescue: The A-plot in the episode "Unleashed" turns out to be this. The victim was living as a Human Pet (the BDSM variant of that trope, though sex seems to be entirely absent from the arrangement) in the mansion of a rich dentist, along with several other women (the arrangement was entirely consensual and the women could have left at any time). Unfortunately, her former assistant (the victim used to work at a shelter for abused women) assumed the victim had been brainwashed and wanted to "free" her, which led to the victim's death.
  • Unwitting Instigator of Doom: A family is seemingly murdered in a home invasion in "Gum Drops", and the motive is revealed when the CS Is discover the family had a large cannabis grow-op in their basement. The daughter is the sole survivor. Her brother and parents were killed when her brother bragged about the family's grow-op to some other kids at school. When some of the brother's school friends came to try and get some cannabis when the brother was supposed to be home alone, his friends shot almost all the family, looted all the dope and cut the little girl's throat.
  • Useless Security Camera: Usually, whenever crimes take place in corner shops, the owner will imply that it's not a real camera (or that it doesn't work) without even having to say it.
  • Vehicle-Roof Body Disposal: A variation in "XX." The killer ties the body to the underside of a prison bus. The body gets chewed up, and the CSI crew initially think they are dealing with a prisoner who was killed why attempting an Underside Ride escape.
  • Vehicular Sabotage:
    • In "Chasing the Bus," the killer pours chloroform inside a bus tire, causing it to suffer a fatal blowout on the road.
    • In "Risky Business Class," the killer sabotages the door seal on a jet, causing it to fail while the plane is in flight. This causes the plane to depressurize and crash.
  • Vengeful Vending Machine: Brass once helped a witness's mother get a soda from the lab's vending machine, which had taken her for $2. He rattled its controls in the right way to get it to cough up the stuck can for her.
  • The 'Verse: In addition to its three spinoff shows, the show also shares a universe with fellow CBS procedurals Cold Case and Without a Trace, the latter of which it crossed over with in season 8.
  • Vignette Episode: "Toe Tags."
  • Villain Episode: "Killer" and "Working Stiffs."
  • Villainous Lineage:
    • Langston fears he may have a genetically inherited violent streak from his father, which is the toned-down version of his original backstory where he fears he may become a serial killer. In an interesting subversion, the person he tells the story of his father (minus the In The Blood part) is the adopted son of the infamous serial killer Judge Mason/Paul Millander, to show that being a serial killer isn't passed down to people who are neither related to nor shown that kind of behavior, despite what his weary mother fears.
    • Played straight with Haskell: His father has been killing for years and his victims include Haskell's mother.
  • Vomiting Cop: In "A Little Murder," Catherine sends a rookie on body-watch outside for some fresh air when she realizes he's about to barf all over her crime scene.
  • Vorpal Pillow: The first Victim of the Week in "Cockroaches" is killed this way. The hitman originally planned to shoot him, but finding the victim asleep, he smothered him instead.
  • We Have the Keys: In "Random Acts of Violence," Gil is searching for evidence in a street when two patrol officers turn up to investigate a possible burglary at an empty and locked house. Discovering the driveway gate is locked, they prepare to climb over it. Gil walks round the corner and finds the side gate is open.
  • Weirdness Censor: One episode that dealt with a murder in a crowded theater referenced "The Invisible Gorilla", one of the most well-known experiments in the history of modern psychology, as an explanation for why a group of bystanders just stood there and ignored a horrible crime happening in their presence: the audience was concentrating so hard on the show that they missed the murder happening right in front of them.
    • "The Invisible Gorilla" operates thusly: a test group watches a video that features six people, three in white shirts, three in black shirts, passing a basketball back and forth. The test group was instructed to carefully count the number of passes made from one white-shirted person to another. Afterward, the test group was asked, "Did you notice the gorilla?" Turns out that at one point in the video, a man in a gorilla costume walks into the middle of the basketball players, thumps his chest a few times, then walks off-stage. In total, the gorilla is onscreen for nearly nine seconds, and no one ever spots it.(even those people who go into the experiment knowing there is going to be a gorilla tend to not spot it at all). The experiment does depend somewhat on context, however—the black gorilla is "irrelevant information" because of the instruction to focus on the white-shirted players. In at least one repeat of the experiment in which the instructions were given to watch the black shirts instead, the gorilla was immediately spotted by nearly everyone.
  • Welcome Episode: Subverted in a major way by having a Welcome Episode premiere which ended with Naïve Newcomer Holly Gribbs getting shot dead. This is then played straight when Sara Sidle is brought in to replace her/act as an independent investigator.
  • "Well Done, Son!" Guy: Presumably Dr. Jekyll's dad. In an interesting twist the dad wanted his son to have a creative career (chef) while the son wanted a more disciplined one (surgeon).
  • Well-Intentioned Extremist: The "neighborhood watch" guy, who can't move due to the economy and has to see an internet porn business and a crackhouse open up on his street.
  • We Should Get Another Tape: In "Let the Seller Beware", the CSIs view a tape where a Trophy Wife had recorded a real estate sales pitch for her house. After the pitch ends, the tape continues and reveals a sex tape she had made showing she was sleeping with her stepson.
  • Wham Line: From the infamous Season 1 episode "Blood Drops:"
    Tina Collins: I learned to deal. But when he went for my daughter
  • What Did You Expect When You Named It ____?: The Body of the Week of the "Angle of Attack" episode turns out to have been killed by a experimental jet engine powered wingsuit that was code named "Project Icarus". This is Lampshaded by Nick.
    Claudia: Uh, okay. I expect you'll want to start with our Project Icarus lab.
    Detective Crawford: Icarus?
    Nick: Icarus. Greek myth. Wax wings, flew too close to the sun. That's a bit of an inauspicious name for a wingsuit project, given the way things turned out for poor old Icarus, don't you think?
  • What Happened to the Mouse?: At the end of a season 3 episode Sara is talking to Grissom about a time she accidently got her brother in big trouble by showing her parents his stash of weed, which she assumed was just a bag of dirt. Said brother would never be brought up again, and the later seasons strongly implied she was an only child.
  • Worst Aid: Usually averted, but in an episode where Nick finds a missing teen who's sprawled unconscious in a ditch after being struck by a car and knocked down a hill, he turns her head as he's checking her injuries. As it happens, when next she's seen on-screen she's mostly paralyzed, in traction and a neck brace...
  • Wounded Gazelle Gambit: In "Frame By Frame", a thief murders her partner during a break-in. When the homeowner returns, trapping her in the house, she binds and gags herself and locks herself in the vault, so she can claim the homeowner abducted her.
  • Wrap It Up: A two-hour movie aired in September 2015 after the series was cancelled in May of that year.
  • Wrench Whack:
    • The Victim of the Week in "Mea Culpa" is a hardware store owner killed by a blow to the head by a monkey wrench.
    • In "Turn of the Screw", the killer beats the Victim of the Week to death a pipe wrench he had just used to sabotage the roller coaster.
  • Wrong Genetic Sex: In one episode, a DNA sample with female chromosomes turned out to belong to a male character. He was a post-operation trans man and it wasn't known that he had been born female-bodied.
  • Wrong Genre Savvy: In "Boom," security guard Dominic is quick to use his expertise in bomb-making (he even blows some up himself in his spare time) to aid the team in the investigation of a bomb at an office building. At least, that's what Dominic thinks is happening. In truth, between his knowledge and his quirky behavior, the team considers him the prime suspect and Dominic goes along, even drawing how the bomb must have been set up, oblivious to how he's implicating himself. When a public defender tries to end a talk, Dominic just brushes her off as "they're being good to me." The team, meanwhile, come to the idea that Dominic is actually playing a twisted game of openly confessing without evidence to play them.
    • It gets to the point where, after a conversation Dominic clearly doesn't realize is actually an interrogation, Grissom openly says he can't tell if the guy is a mastermind playing them or "just crazy."
    • The answer comes when Dominic dies stopping a bomb from going off in a school and the team realize he really was a hero trying to help them out.
  • You Need to Get Laid: When Nick jokingly tells his nerdy Lab Rat coworkers they need to get a girlfriend, it backfires both times. David reminds Nick he's engaged, and Archie just scoffs, "You first!"
  • Your Mom:
    • Haskell goads the guard outside his cell by saying Dr. Jekyll was the guard’s mom.
    • A visit to a brothel to get information on a guy who had been there gets someone telling Nick “your mother slept with Azerbaijani!”
  • Your Other Left: In "Alter Boys", Sara is taking a suspect's boot prints and tells him to raise his right foot, followed immediately by "Your other right".


The CSI video games provide examples of (in addition to many listed above)

  • Art Evolution: Just look at the graphics for Fatal Conspiracy, and then look back at the very first CSI game. Yeah...
  • A Winner Is You: After you beat a case with 100% completion, you usually just get Grissom telling you that doesn't happen often, and that he's very impressed. If you don't get 100%, he just berates you and tells you to try better next time. To be fair though, it is in character for Grissom to give you such a bare minimum evaluation. In the games made after William Petersen's departure Catherine gives you a more glowing evaluation, making you feel like you really accomplished something. However, she pretty much says the same thing regardless if you get 100% or not.
  • Back Tracking: The amount of times you have to keep going back to a crime scene, or a suspect's place (just to gather more evidence, or get more information) is a little ridiculous and unrealistic, especially when compared to the TV show. The game designers sort of lampshade it though sometimes by having the suspects get really agitated with you everytime you come back to get more info, or look for more evidence.
  • Brick Joke: Each CSI game comes with 5 cases. For every 5th case, a suspect from an earlier case who was later deemed innocent shows back up again, and usually turns out to be heavily involved with the current case, or is the actual murderer.
  • Character Tics: Some suspects have these, and they become essential to the case later. One female suspect in one game keeps fidgeting with her fingernails during questioning. It's later revealed because she broke a fake nail, and the broken piece turns up on the victim's dead body.
  • Early Installment Weirdness: The very first CSI game had poor graphics, and the characters just barely resemble the actors from the TV show. The cases were much shorter, and in the first two games, Greg did all DNA, print, and chemical matches for you.
  • Face–Heel Turn: Practically a fleet of police officers and undercover agents in the game Fatal Conspiracy.


Alternative Title(s): CSI Crime Scene Investigation

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