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Dr. Gilbert "Gil" Grissom
Played by: William Petersen
- Alliterative Name
- Ambiguous Disorder: He displays the combination of extremely high intelligence and extremely low social skills that is stereotypically associated with Asperger's syndrome and other forms of high-functioning autism, but nothing is ever stated for certain.
- Badass Bookworm
- Berserk Button: Drug dealers, especially those who sell to young people, and scientists who sell their integrity for personal gain.
Grissom: "There's three things I got a real problem with: Guys that hit their wives, sexual assault on children and the scum that deal death to kids."
- And anyone who tries to hurt Sara. Pity that didn't include him.
- In-universe, Grissom cites three Berserk buttons
- Broken Pedestal: Both his old professor and a colleague he wrote a study with became, to quote him, "guns for hire," selling their forensic skills to help rich guilty clients beat the rap.
- Bunny-Ears Lawyer: He quotes Shakespeare, loves crossword puzzles, and races cockroaches for fun.
- The Bus Came Back: He returns to the show after a while off-camera for the Grand Finale.
- Cannot Spit It Out: His feelings for Sara in the first couple of seasons, even being so unsure about a possible commitment to the point where he rejects her initial advances.
- Cool Old Guy
- A Father to His Men: His paternal leadership style, especially visible with Greg, Nick and Warrick especially right before Warrick gets killed, and afterwards.
- Flanderization In regards to his stoicism. In the first season, he was prone to bouts of anger (once slapping a coffee pot out of Ecklie's hand, enraged) and happiness (even—gasp—smiling! With teeth and all!). By Season 3, his character was shaped into being level-headed at all times, even in normal conversation. Justifiable in that he starts to retreat emotionally during his struggle with his hearing loss.
- Friend to Bugs
- Game of Nerds: He likes baseball.
- Innocently Insensitive: His distant approach to social life leads him to sometimes saying the wrong things without realizing it, specifically to Sara before they dated, much to her frustration (she nearly quits over it).
- Intelligence Equals Isolation: Especially in the earlier seasons. Despite his intelligence and expert grasp of human nature, Grissom led a very isolated life, and rebuffed most opportunities of interaction outside of the workplace. He even turned down Sara's initial dating requests in Season 3.
- Married to the Job : For most of the series, at least until he married Sara. Catherine used to tell him to take his head out of his microscope once in a while.
- Nice Hat: Seen sporting a straw sunhat in more than one episode. It was once complimented by a hooker.
- And that hat belongs to Petersen himself acquired from his own travels.
- Not That Kind of Doctor
- Papa Wolf: Pretty much the only way to get him riled up is to either threaten one of his teammates, especially Sara, or do anything to endanger children
- Platonic Life Partners: With Catherine. They are obviously best friends, but there's also no hint of sexual chemistry between them.
- Put on a Bus: After season 9.
- The Bus Came Back: He did have a cameo in season 12's "The Two Mrs.Grissoms", and returned at last for the series finale in September 2015.
- Quip to Black: Famous for it — used to be the Trope Namer
- Sarcasm Failure: When he doesn't use the above
- Science Hero
- Seeker Archetype
- Serious Business: Racing cockroaches. One of the first time we see him take some time off and puts Catherine in charge is when he goes to a conference to race his vermin. It doesn't go so well ("Stage fright.")
- Silver Fox: Despite his nerdiness and aloofness, he still gathers a lot of female admirers (in-universe and out), even when he shies away from the unwanted attention. He had no problems getting dinner dates when he actually sought them out.
- The Smart Guy
- The Spock
- Team Dad: To the boys more than Sara (obviously), but especially to Warrick and Nick.
Played by: Marg Helgenberger
- Action Girl: She can stand up for herself when she needs to.
- The Bus Came Back: Another Grand Finale example.
- Deadpan Snarker
- Faking the Dead: With D.B. to escape the bad guys before her departure
- Fiery Redhead
- Heroic Bastard: It's established early on that she was raised by a single mother, but it's only later that she learns her father is Sam Braun, who leaves her a chunk of his casino after he dies.
- Mama Bear: Messing with her daughter? Big mistake. The same applies to her team members
- Ms. Fanservice: She used to be a stripper, way back in the day (and not an Old Shame for her, even when a DA tries to use it against her in court). She's had a couple of Toplessness from the Back scenes and an interrogation where she unbuttoned her blouse every time her suspect gave her an answer.
- Official Couple: With Vartaan. For a while, anyway.
- Platonic Life Partners: With Grissom.
- Put on a Bus: Season 12. She's with the FBI now.
- The Bus Came Back: Like Grissom, came back to Vegas for the series finale case, which started at the casino she inherited, and decided to stay.
- Revenge Before Reason: Her automatic hatred towards registered sex offenders and anyone she even suspects of being a child abuser.
- The long version: Catherine has several times had a very strong reaction to cases where a little girl is the victim of their case, to the point where she will allow her own emotions to cloud her judgement. It is hinted this is because she is the mother of a young girl. Her emotions have caused her to severely jump the gun when it comes to a suspect and showing no hesitation to add her own verbal disgust and disbelief towards a suspect when they tells her their side of the story. Sara even once lampshaded this by snarking that it was "fun" to hear Catherine's theories rather than process the actual evidence. Ironically, every time she has let her emotions take control of a case like this, who her hatred is focused towards has always turned out to be a mere victim of "being at the wrong place at wrong time", shown by the evidence they were in no way involved with the case, but by the time that is revealed she often has completely ruined said guy's life.
- Brutal case in point being Leo Finley from "A Thousand Days on Earth". She believed he was a child molester because of his name on the Sexual Predator Watch List though he was only there because of an incident where he got high on hallucinogenics and walked out naked in front of a bus full of children. After the man's fiance found out about his past (through Catherine vindictively outing him) and that he was using an assumed name, she kicked him out of the house and then got him fired by telling his boss. The man walked up to Catherine in the parking lot after this, threatening to shoot himself in the head on her front lawn one day, even calling her a "blonde Nazi bitch" when she insists she was just doing her job.
- Scare 'em Straight: In response to Lindsey's reckless hitchhiking, her mom drags her into the morgue to view a dead hitchhiker (to Dr. Robbins' disapproval).
- Screw the Rules, I Have Connections!: Her being Sam Braun's daughter has gotten things done with her superiors at least once, even after his death.Brass: Unbelievable! Sam Braun has more influence dead than I do alive!
- Ship Tease: With Warrick, up until his marriage. She even referred to the event as the "end of a fantasy".
- Single Mom Stripper: Retired.
- Team Mom
- "Well Done, Son!" Guy: Old-school casino owner Sam Braun, who is shifty to say the least.
Played by: George Eads
- Berserk Button: Harming children in general, though sexual assault especially gets to him since he was molested by his babysitter as a kid.
- Buried Alive
- Curtains Match the Window
- Dark and Troubled Past
- Friend to All Children: To the point that the other CS Is automatically defer to him when a child becomes involved.
- Manly Tears: Nick has cried several times over the course of the show, and it serves to highlight his empathetic nature.
- Mr. Fanservice
- Lantern Jaw of Justice
- Nice Guy
- Porn Stache: For a while, before he had enough of everyone's justified ribbing.
- Put on a Bus: To run the San Diego crime lab in the season 15 finale, though it took him a while to decide what with Finley in a coma and all, but DB assures him it's what she would've wanted.
- Really Left Montage: at the end of the episode.
- Shirtless Scene
- Southern Gentleman
- Taught by Television: "I watch the Discovery Channel," was one of his regular comments, back in the days when you learned things from the Discovery Channel. He switched to Animal Planet once or twice.
Played by: Gary Dourdan
- The Atoner
- The Big Guy
- Deadpan Snarker
- Fatal Flaw: His gambling addition and all of the problems that come with it.
- The Gambling Addict: His addiction gets him into trouble early in the series, though he gets better.
- Genius Bruiser: He's the largest and most physical of the original team, but that doesn't stop him from being a trained Audio/Visual expert who can count cards in his head.
- Killed Off for Real: Shot in the throat by Undersheriff Jeffrey Mc Keen.
- Out of Focus: Got hit with this hard and ended up being one of the least developed members of the cast.
- Stuffed in the Fridge: Essentially. He wasn't exactly dead when Grissom found him, but he was close enough.
- Scary Black Man
- Token Minority
Played by: Jorja Fox
- Alliterative Name
- Berserk Button: Domestic violence, especially spouses murdering each other.
- Broken Bird
- Commuting on a Bus: As of Season 10, she's on the line...she's listed as a series regular, but only appears in a certain number of episodes per season.
- The Bus Came Back: Returned to C.S.I. full-time in Season 11, and remained aboard for the rest of the show's run.
- Dark and Troubled Past: Her mother killed her father, who was abusive to both her and her mother. She ended up in foster care.
- Not to mention the stuff that's happened to her since.
- Freudian Excuse
- Hint Dropping: Tries this as a tactic while trying to court Grissom. She once told Hodges (who was fretting about a possible grey hair) that she finds grey hair rather sexy, while standing next to Grissom. Eventually, she point-blank asks him out, which he refuses. After a couple of more years, he eventually comes around to Glad You Thought of It.
- Hot For Supervisor
- The Lancer
- The Maiden Name Debate: She still uses "Sidle" now that she is married to Grissom. Now that she is separated from him as of Season 13, the question is now moot.
- Married to the Job: At least until she married Grissom. Divorced by the time the bus came back; back with him by the end of the series finale.
- May–December Romance: With Grissom; the actors are 16 years apart in real life. Not that it matters to Sara, who as mentioned above, has a thing for silver foxes.
- Put on a Bus: She's taken a round trip, having come back to assist the team when they're short-staffed in season 10.
- The Bus Came Back: She's an official series regular again for Season 12.
- Relationship Reveal: with Grissom
- Second Episode Introduction: Comes in to help the team per request of (who else?) Grissom in the second episode following the death of the Naïve Newcomer and stays on board.
- UST: For YEARS with Grissom before Season 6 ended with the above trope.
Played by: Eric Szmanda
- Break the Cutie: He becomes noticeably more mature after getting beaten to near death in "Fannysmackin'".
- Casual Kink: Has dabbled in every fetish under the sun, including latex wear, S&M, and even plus-size women. This is a man who likes variety.
- Deadpan Snarker
- Delinquent Hair
- Expository Hairstyle Change: Shortly after becoming a CSI he stops sporting his normally wacky hairstyles, to show how he's matured.
- Genius Ditz: In earlier seasons. While he does act like an idiot he's very good at his job, and has extended knowledge on coin collection and Old Vegas.
- I *Might* See Dead People / Maybe Magic, Maybe Mundane: His grandmother had "the Sight" and the psychic who sensed his grandma tells him he has it too. One the one hand he couldn't detect anything when he was in the "haunted" slaughterhouse with the killer, on the other one could argue the spirits were being really quiet so he could hear the killer's ringtone, which was caught on tape by the psychic before she was killed.
- The Intern
- The Lab Rat/Misfit Lab Rat: At first.
- Ascended Fanboy: from "CSI Wannabe" to actual CSI.
- Likes Older Women: If his apparent attractions to a Dolly Parton-lookalike gambling maven ("Revenge Is Best Served Cold") and a fading ex-showgirl legend ("Kiss Kiss, Bye Bye") are any indication...
- My Beloved Smother: She took him to the ER for a bloody nose.
- Out of Focus: From Season 9 onwards.
- Plucky Comic Relief
- Promotion to Opening Titles
- The Reliable One
- You, Get Me Coffee
Dr. Raymond Langston
Played by: Laurence Fishburne
- Enemy Within: He possesses the same "serial killer" gene that Nate Haskell has
- Extreme Melee Revenge: Does this to Haskell in "In A Dark, Dark House."
- Freudian Excuse: Played with. His father was apparently violent, and Raymond worries that he may become that way himself. He also has a gene that has been associated with violent behaviour. On the other hand, when faced with Serial Killer Nate Haskell, who has the same gene and his own abusive father, he testifies in open court against his attempt to use this card, and afterwards Haskell admits to him that he decided in his youth he'd blame it on those things if he were ever caught.
- I Am Not My Father
- Not That Kind of Doctor: Inverted, he is that kind of doctor (or rather, he used to be).
- The Professor
- Put on a Bus: After killing Haskell, he is discharged from CSI by IAB and sent back to the east coast with his former ex-wife. He's mentioned once in the Season 12 opener, but is completely dropped from the series afterwards and essentially completing his character arc; he's one of a handful of living characters that doesn't return for the series finale.
- Token Minority
Played by: Lauren Lee Smith
Played by: Ted Danson
- Bunny-Ears Lawyer: Almost as much, if not more, than Grissom.
- Cloudcuckoolander: Sometimes, at least.
- Cool Old Guy
- Do Not Call Me "Paul": See below for why.
- Embarrassing First Name: Diebenkorn Russell.
- Faking the Dead: Does it with Catherine to escape the posse of hitmen after them.
- Also in his premiere as well as he is posing as a dead body for "investigative purposes".
- I Have Your Wife: McKeen's people do this to him with his granddaughter in the Season 12 finale.
- Happily Married: The only CSI to be this from the beginning, although things get strained later on when his granddaughter is kidnapped (There's Grissom and Sara, but that came later).
- In CSI: Cyber he's divorced.
- Suspiciously Similar Substitute: Not to Langston, but rather Grissom.
- Team Dad: Picking up where Grissom left off, but in a different kind of way since D.B. is a literal father as well. He's especially this trope for Greg and Morgan, the two youngest CSIs. (Morgan's actual father, Ecklie, practically states this trope directly in CSI Down.) He now acts as this on the fourth spinoff, CSI: Cyber.
- True Companions: He regards the CSI team as this. They're a little weirded out by it.
- Unfortunate Name: Diebenkorn.
Played by: Elisabeth Harnois
- Heroic B.S.O.D.: She's showing some signs of this following her abduction and shooting in season 14.
- Hot Scientist:Greg: That's Ecklie's daughter?
- Ms. Fanservice: Wears more makeup than the other team members and her clip in the titles involves her running in a tight white T-shirt.
- Parental Abandonment: Ecklie left when she was 14. She uses the surname of her stepfather.
- Ship Tease: Several moments with Greg and, believe it or not, Hodges, whom she pretends to date to impress his mother.
- Vitriolic Best Buds: A Type II with Greg and Sara is shaping up.
- Absolutely has this with Hodges. They bicker frequently, but clearly care about each other. Morgan actually flat-out refers to him as her best friend, and even once agreed to pretend to date him in order to get his mother off his back. (And now that her father is dating his mother, well, both the bickering and the caring have gotten more interesting.)
- "Well Done, Daughter" Girl: Seems to have a bit of this with her father Ecklie.
Julie 'Finn' Finlay
Played by: Elisabeth Shue
- Berserk Button: Corporate crime, and especially powerful people who get away with crimes due to connections.
- Convenient Coma: Ends Season 15 in this spot after being brutally beaten and stabbed by the Gig Harbor Killer. With Elisabeth electing not to come back for the series finale movie, it seems unlikely she's ever going to wake up. The Grand Finale confirms she died.
- Do Not Call Me "Paul": D.B. is the only person who'll call her 'Jules' and she doesn't like it. She prefers Finn. Interestingly, D.B.'s wife also calls her 'Jules', and she doesn't even react.
- Last Name Basis: Sort of.
- Sleeves Are for Wimps: The most likely of the final female team to not wear sleeves.
Dr. Albert "Al" Robbins
Played by: Robert David Hall
- Berserk Button: He absolutely HATES rats, even if it only showed in one episode, aptly titled "Lab Rats".
- More commonly seen is his tendency to get incredibly testy when he sees evidence of another medical examiner (or a paramedic, or police officer) cutting corners or not following protocol. And don't even think about suggesting that he was less than thorough about doing his own job.
- The Coroner
- Genius Cripple
- Handicapped Badass: He might need a cane to get around, but he can be a pretty mean fighter when he has to be.
- Happily Married: Besides a few issues, he's one of two CSI employees, the other being D.B. Russell, to be this.
- The Lab Rat: Sort of, although he's a mortuary rat rather than a lab rat.
- Mr. Exposition: His autopsies often reveal further background on the murder victims.
- Sympathetic Adulterer/Your Cheating Heart: Reveals in season 12 that he cheated once, essentially just to see if he had the guts to. It nearly ruined him and his wife, and they've been faithful ever since. It's really kind of adorable.
- Why Did It Have to Be Snakes?: Rats.
- Written-In Infirmity/Disabled Character, Disabled Actor: Both Robert David Hall and Albert Robbins are double amputees.
Played by: David Berman
- Adorkable: Evident in one episode during his high school reunion, see Ugly Guy, Hot Wife.
- Catch-Phrase: "Sorry I'm late..."
- The Coroner: Though he's only an assistant to the actual ME, Dr. Robbins.
- Fan Nickname: He's only been called Super Dave a handful of times in-universe, but the name's stuck with the fans.
- The Lab Rat
- Plucky Comic Relief: He gets this treatment sometimes.
- Promotion to Opening Titles
- Shown Their Work: Berman is the head researcher for the show.
- Ugly Guy, Hot Wife: He's not bad looking but compared to his absolutely beautiful (and very pregnant) wife in one episode where he goes to his high-school reunion.
Played by: Wallace Langham
- Born Lucky: But only on a single day: April 7th. Its his lucky day. On this day, nothing has ever gone wrong for him, ever. In "Lab Rats" he took advantage of it being his lucky day to help crack a case that even Grissom couldn't figure out.
- Brilliant, but Lazy: Unlike most Lab Rat characters on the CSI shows, Hodges is quite content to remain indoors and hates going into the field.
- Bunny-Ears Lawyer
- Deadpan Snarker
- Hidden Depths: Among other things he's a big sci-fi geek, with an undying love for "Astro Quest" (an Expy of Star Trek: The Original Series).
- Jerkass and/or Jerkass Façade (up for debate)
- Large Ham: Has his moments, but the "Astro Quest" episode (and the dream sequences that had Hodges as The Captain of the Show Within a Show) were pretty much a chance for Langham to unleash his inner William Shatner in a homage to "The Gamesters Of Triskelion".
- Momma's Boy: He was living with his mother when he first started working at the lab. When she finally appears on-screen, we learn that she's a surprisingly attractive and classy lady, and far from the typical My Beloved Smother that most mothers involved in this trope are.
- Pet the Dog/Establishing Character Moment: For the first couple seasons he was on the show, he was portrayed as a through-and-through Jerkass Professional Butt-Kisser with no redeeming qualities whom all his co-workers hated. In Season 7, however, he gets a surprising amount of Character Development in a scene where he has to break the bad news to a victim's family, and he's been portrayed as a sympathetic character ever since and even joined the main cast.
- Promotion to Opening Titles
- The Reliable One
- Small Name, Big Ego: He acts like he's much more important than everyone else. Can occasionally cross into Insufferable Genius.
- Why Did It Have to Be Snakes?: Birds
Played by: Liz Vassey
Played by: Sheeri Rappaport
Played by: Archie Kao
Played by: Jon Wellner
Played by: Eric Stonestreet
Captain Jim Brass
Played by: Paul Guilfoyle
- All of the Other Reindeer: A Bullet Runs Through It, where the other cops shun him at the dead officer's funeral.
- Berserk Button: Bad fathers, likely because he wishes he could've been a better one.
- Cool Old Guy
- Deadpan Snarker: On Vegas' staggeringly-high murder rate: "We're very competitive!"
- Dirty Cop : Originally a big subversion of this, stating how he refused to be bought or get dirty, but now drifting into that territory as of the end of season 11. He covered for Ray when Ray killed Nate Haskell, and was reluctant to help catch a killer who was killing other killers.
- Et Tu, Officers?: In the episode, "A Bullet Runs Through It", he felt this way when one by one, all of the other officers walk away from him at the dead officer's funeral.
- Jerkass In Season 1.
- Jerk with a Heart of Gold: Eventually mellows out into this.
- Mr. Exposition: He's the man who gives both the team and the audience information on the latest victim of the week.
- Outranking Your Job: Spends a lot of time personally investigating crime scenes and chasing down suspects for a police captain.
- Parental Issues: He still loves his daughter despite knowing that she's not his. Her... not so much, to the point that when Brass is shot he gives power of attorney to Grissom rather than to her.
- Put on a Bus: Took a leave of absence for season 15 after his daughter faked her kidnapping with the help of a boyfriend, got Brody involved and almost killed her, killed the boyfriend, and killed her mother (who she didn't expect to come to Las Vegas) because she would have recognized the boyfriend. Amazingly Brass is helping her with her trial.
- The Bus Came Back: Came back for the finale.
- Semper Fi: Vietnam Marine vet.
- Your Cheating Heart: He and his ex-wife mutually cheated on each other before their divorce, and he knows that his daughter isn't actually his.
Played by: Louise Lombard
- Action Girl: Oh yeah. And given her profession, it's absolutely necessary for her survival.
- Brother Chuck: Was a semi regular for three seasons, a regular character in one season, and then vanished without a trace, or explanation.
- Fair Cop
- Heroic B.S.O.D.: In the episode "A Bullet Runs Through It", when she believes she shot a fellow cop.
- Mr. Exposition: Basically, a female Jim Brass.
- Rank Up: Now she's Brass's boss.
Played by: Marc Vann
- A Day in the Limelight: The B-plot of one episode featured Ecklie handling the investigation himself when the main characters were unavailable.
- Ambition Is Evil: The real reason he was such an ass to Grissom and the team was because he thought that Grissom had the same ambitions he did. Once he realized that Grissom and the team wouldn't keep him from fulfilling his goals, he eased off considerably.
- His behavior in the season 14 episode "Consumed," though, suggests that running for sheriff may cause him to relapse.
- Big Bad: Arguably, of season five. He never does anything illegal, but his antagonistic actions drive the overarching plot of that season.
- Character Development: A fairly significant example of this. He's almost a completely different person now than he was in season 1. He makes a pretty seamless transition from Jerkass to Jerk with a Heart of Gold. After 13 seasons he's still can be a bit nasty at times, but he has the respect of the team and the department as a whole, and he's absolutely a Reasonable Authority Figure now. (He's aware of it, too: when he talks to Morgan about being offered the sheriff position, he admits that part of the reason he isn't sure about it is because he's afraid he'll revert to the manipulative asshole he used to be.)
- Da Chief: He starts out as the day shift supervisor, then becomes director of the lab, and is later promoted to undersheriff of the entire department.
- Diabolus ex Machina: Supplies a rather nasty and completely out-of-nowhere one in "Fracked". (Though, granted, it's fairly clear that there's not much he can do.)
- Heroic B.S.O.D.: This is debatably the cause of his considering leaving his job in season 13. He doesn't show any signs of being tired of his job until the corruption of the department and his shooting.
- Jerkass: Definitely one pre-Season 6.
- Jerk with a Heart of Gold: Developed into one, and a Reasonable Authority Figure, pretty nicely afterwards. His statement that he would've helped Grissom and Sara avoid any conflicts because of their relationship certainly sounded genuine, and he's been mostly a lot nicer to the team while still keeping his prickly attitude. Come the later seasons, and he's been even better with Morgan around.
- Obstructive Bureaucrat: He's extremely ambitious, and saw Grissom as competition. At different points, he would try and undermine the team's work.
- Parental Abandonment: He left when Morgan was 14.
- Rank Up: To Undersheriff and eventually Sheriff.
- Reasonable Authority Figure: When Nick was Buried Alive, Ecklie pulled some strings to gather the ransom his kidnapper, and relations between him and the night shift have mostly thawed since then. Ecklie came into his own as Asst. Director, where his talent for juggling the top brass and news media have proven to be an asset to the team.
- Now he's the new sheriff, and he seems to have kept his reasonableness. The only time so far that he's really pushed back against the team is when he's faced with having to give permission for his own daughter to be used as bait for a serial killer. A perfect example of his reasonable attitude is when Finn and Nick clash with a fire investigator at an arson scene. The investigator calls in Ecklie with "concerns" about their methods, and before passing any judgements, Ecklie hears Nick and Finn out and even takes his jacket off and helps them dig through a burnt-out building to prove their theory.
- The Rival: To Grissom, who deplores Ecklie's careerism.
- Smug Snake: Pre-"Grave Danger." He took utmost pleasure in seeing Grissom's team humiliated, and even worked to get Nick convicted of murder once purely out of spite.
- Taking the Bullet: For his daughter when he gets gunned down in Homecoming. It's possible that they had been aiming intentionally for him, but given that he shot McKeen's son, it seems likely that Morgan was the target.
Played by: Conor O'Farrell
- Ambition Is Evil: Brass recalls that when he was made a detective, McKeen invited all of the new detectives over to his (suspiciously large) house for a barbecue. When Brass let him known that he wasn't such a careerist that could be bought like that, he was never invited again, and had to watch over the years as all the others at that barbecue were promoted above him.
- Big Bad: Of Season 8, the 12 finale, and the premiere of 13.
- Clueless Detective: Doesn't always get or appreciate the abilities of the CSI's or what they do which bites him in the ass when he tries to frame someone else for murder.
- Commander Contrarian
- Implacable Man: Crashes his car at high speed when shot by his paranoid passenger, and drags himself away from the wreckage to bleed out...and lives,despite his best efforts.
- Jerk with a Heart of Gold:Subverted. He seems like that at times...until he murders Warrick in cold blood.
- Might as Well Not Be in Prison at All: "Homecoming" reveals that he's still running his criminal machinations from prison.
- The Mole
- Obstructive Bureaucrat
- Professional Butt-Kisser
- The Sheriff: Well, his title is Undersheriff.
- Suicide by Cop: Attempts this with Nick, but Nick doesn't go through with it.
Played by: Melinda Clarke
- Brains and Bondage: A licensed therapist... who also happens to run an S&M club.
- The Bus Came Back: Really never appeared after William Petersen/Grissom stopped starring in the show, only appearing once for a case in Season 11. She returned as a suspect yet again in one of the most massive cases to hit the show in C.S.I.'s series finale.
- Driven to Suicide: Sort of. In one episode, she hires a guy to kill her because she lost custody of her granddaughter. She lives, though.
- Drop-In Character: Cases have a weird way of tracing back to her.
- Ethical Slut: As befits her profession as a Dominatrix.
- Good People Have Good Sex: In a series that generally conforms to this trope, she remains the one notable aversion. Her practices still make her dark and troubled, however.
- The Maiden Name Debate: Strangely enough, she apparently took her husband's name.
- Mama Bear: Do not mess with her daughter. She WILL perform her S&M routine on you to make it hurt before she kills you.
- Of Corsets Sexy: Wearing one when we first meet her.
- Playing Gertrude: Melinda Clarke was 32 when she first played the role of a character who, given her daughter's age, was probably intended to be in her early forties. Melinda wasn't even 40 by the time Heather became a grandmother in the show.
- Stuffed into the Fridge: Not Heather herself, but in the Grand Finale her toddler granddaughter is offhandedly revealed to have been killed in a car accident, which serves little purpose other than driving Heather across the Despair Event Horizon so she can be a murder suspect. She pulls the plug on her practice after her granddaughter died, which helped set up the plot of the Grand Finale.
- The Vamp: Used for good! In her third appearance, she sleeps with Leon Sneller, the guy who killed her daughter to get evidence from him to give the team.
- Whip It Good: Used horrifyingly in "Pirates of the Third Reich" when she captures Sneller, ties him to her car, and proceeds to try to whip him to death. Grissom talks her out of it.
Played by: Scott Wilson
- Big, Screwed-Up Family: One son is a murderer, the other a heartless casino shark, and Sam himself might possibly be both. At least there's Catherine.
- Cain and Abel: One of his sons killed the other out of jealousy.
- Catherine, I Am Your Father: We'd been informed he was an ex-boyfriend of her mother in prior episodes, so there was some foreshadowing.
- Corrupt Casino Head
- Dirty Old Man: Definitely seems to prefer his women a full generation younger than him.
- Disappeared Dad
- The Don: Gives off this impression, but nothing's ever proven beyond this.
- Drop-In Character: It's apparently a small Vegas after all, because like Heather, his name comes up in a frankly absurd amount of cases. The difference, of course, being that while Heather usually takes the role of key witness, Sam being who he is is often the prime suspect.
- Karma Houdini/Not Proven: He was a suspect in a murder from decades ago, and Catherine wholeheartedly believes it was him, but there was another suspect whom all the evidence seemed to point to and Sam is never charged.
- Kick the Dog: Organizing the bank robbery that gets Detective Lockwood killed. Kept from being a full-on Moral Event Horizon-crossing by the fact that Sam didn't intend anyone to die and the Ax-Crazy head robber went off the rails, but the fact that he was willing to put innocent people and lovable supporting cast members in a life-threatening situation purely for his own benefit is a pretty huge dick move.
- Morality Pet: Catherine. He also expresses genuine affection for Catherine's mother and Lindsay, but is never seen interacting with them on-screen.
- Pet the Dog: Hates himself for favoring his older son, leading to the jealous younger one killing him.
- Red Herring: No matter how good him motive or opportunity might've been, he is always this.
- Sleazy and Hedonistic Old Folks
- Vigilante Execution: ...by the domestic partner of a man Braun had financially ruined.
Paul Millander/The Bathtub Killer
Played by: Matt O'Toole
- Big Bad: Of the pilot and a good chunk of the first two seasons.
- Chekhov's Gun: The rubber hands he made in his shop, the hand impression his father made for him, and the ID his son made for Grissom all turn out to be crucial to the case.
- The Chessmaster: Far smarter than the entire team put together.
- Dark Is Evil: Before going on the run he was the owner of a shop that sold seriously grisly Halloween props.
- Evil Counterpart: To Grissom; bonus points for being the first major C.S.I. nemesis to ever appear in the franchise.
- Freudian Excuse: He (or rather, "she" at the time) watched as his father was murdered and the death made to look like a suicide in his own home, and then his testimony was thrown out at the trial and the killers went free.
- Hanging Judge: In his Secret Identity
- The Heavy: For much of seasons 1 and 2.
- Karma Houdini: Of a sort; he commits suicide, in the same way he killed his victims no less, to deny Grissom the satisfaction of sending him to jail.
- Mommy Issues: His mother ostracized him after his operation. He repays her with a knife to the gut.
- That One Case: For Grissom. One of Millander's victims is the primary victim of the pilot episode.
- Pet the Dog: Revealed posthumously; he honestly loved his adopted son.
- Secret Identity: As a judge, complete with a family who know nothing of his murderous ways.
- Serial Killer: The series's first, and the setter of the standard for season-long arcs focusing on serial killers for both this and the other C.S.I. shows.
- Series Continuity Error: A major plot point in his last episode is that he and his father have the same name... except that the elder Millander's name was given as "John" in a prior episode.
- Transsexual: He felt the reason his father's killers went free after his testimony was thrown out was that he was a girl and therefore "weak," so he decided to become a man, though it was implied he had gender identity issues going further back than this.
The Miniature Killer/ Natalie Davis
Played By: Jessie Collins
- Arch-Enemy: Quickly becomes this to Gil Grissom, especially after she kidnaps Sara and leaves her for dead.
- Ax-Crazy: Key word: Bleach. Say this to her or make any indication of the thing and you're dead.
- Big Bad: Of Season 7 and the first episode of Season 8.
- The Jail Bus Came Back Davis returns in one of Peterson's last episodes for a hearing about whether or not to transfer her to prison, which they do. She has worked over her bleach problem by this time.
- The Heavy: Has this on Grissom long after she's in prison, only matched by Millander and later Nate Haskell for Ray Langston.
- That One Case: One of the most unique villains in the history of the C.S.I. franchise, her entire M.O. with creating miniatures of future murder scenes then executing the scene to exacting standards became a hot topic both in the show and in real life for the 2006-2007 TV season.
- The Unfavorite: She was this as a kid, and it's implied her first kill was her older sister, in an attempt to finally get attention.
- Villainous Breakdown: When she's finally arrested, Grissom's attempt to force Sara's location out of her drops her into a catatonic state that requires her to be institutionalized.
Nate Haskell/The Dick & Jane Killer
Played by: Bill Irwin
- Abusive Parent: His father was a drunk who would beat him and his mother.
- All Girls Want Bad Boys: This monster has a "bride" fanclub.
- Arch-Enemy: To Raymond Langston
- Asshole Victim: After all he's done, it's hard to feel sorry for him after Raymond Langston kills him.
- Attention Whore: After being caught, he pled not guilty, but later confessed when his defense claimed that his crimes could only be committed by multiple people working together. He was also the only murderer to accept the opportunity to speak to a class during a lecture.
- Ax-Crazy: As Brass put it, "He's like the Joker from Batman, except without the laughs."
- Big Bad: Of Langston's intro episode halfway through Season 9 (this was also Grissom's final regular story arc as a character until the series finale), and of Season 11. His death is was ends Langston's character arc and his time in C.S.I.; Fishburne was asked to leave at that point and was replaced by Ted Danson.
- Blatant Lies: While torturing his victims, he would offer them a chance to survive. They never did.
- Chick Magnet: While in prison he was proposed to a few times.
- Dark and Troubled Past: Was abused by his father and listened to him kill his mother when he was eight.
- Enemy Mine: Helped the CSI team find Dr. Jekyll. He uses the whole thing to ultimately set up his escape.
- Four Eyes, Zero Soul
- Freudian Excuse: His dad beat his mom to death and made him listen to her screams.
- I Have You Now, My Pretty: Kidnapped Langston's ex-wife and raped her, among other things.
- In the Back: Stabbed Langston there in the 10th season finale.
- The Heavy: This guy's specter hangs over the C.S.I.s from his first appearance to just past his death when his saga results in Langston being forced out and Catherine and Nick getting demoted back to their original positions from when Grissom dealt with Haskell; this leads to Catherine's own exit from the lab later.
- Kill and Replace: "Nate Haskell" turns out to have been the name of his first victim, a traveling salesman whose identity he stole. His real name is "Warner Thorpe."
- You Have Outlived Your Usefulness: Does this to his final Monster Fangirl, after most of the others kill one another.
Dr. Jekyll/ Chef Charlie Dimasa
Played by: Matt Ross
- Arch-Enemy: To Ray in Season 10; he loses this position back to Nate Haskell after he's killed.
- Big Bad: Of Season 10.
- The Heavy: Ray is really troubled by this suspect, especially when they meet in a hospital and Jekyll steal's Ray's ID card, which he mails back along with prosciutto that had a Jane Doe number of an earlier botched victim on it; this is how they identify him when they match DNA he left to his father's septic appendix, which was found in his second victim (and the first one he actually killed) earlier in the season.
- Meatgrinder Surgery: Subverted; he took great care when performing his surgeries/murders, which did not help the case at all.
- Secret Identity: Dr. Jekyll turns out to not be a doctor at all, but a cook in a luxurious Italian restaurant who had to drop out of medical school to assist his father. He did well as a chef, but did not take the whole thing well at all, hence his literal butchering surgery on the season's victims.
- That One Case: Jekyll's odd surgeries (starting with someone who was already dead, but moving on to actual murder thru surgery after the C.S.I. trilogy) stumped Langston and Dr. Robbins throughout the show's 10th anniversary, which Langston taking his work home. They eventually had to enlist Nate Haskell, the Big Bad of Ray's introduction episodes, to finally bullseye Jekyll, but this move leads to the Season 11 plotline and the events that end in Langston and Catherine's departures from the crime lab.
- Villainous Breakdown: When Langston and Stokes find him, he finally turns on the Mr. Hyde persona for the first and only time by grabbing a shotgun, blowing the head off a cop, and shooting up his restaurant and trapping everyone there.
Played by: Justin Bieber