Clue, Evidence, and a Smoking Gun

"The battery was a lithium thionyl chloride nonrechargeable. I figured that out from some subtle clues: the shape of the connection points, the thickness of the insulation, and the fact that it had 'LiSOCl2 NON-RCHRG' written on it."

—Mark Watney, The Martian

Sometimes deduction takes leaps of logic to come to a simple conclusion based on very minor details. Sometimes it's obvious. Sometimes however, the deductor uses his Bat Deduction or Sherlock Scan skills to explain his conclusion, and then adds a Smoking Gun for good measure, making the previous deductions quite redundant.

As a subversion, the deductor may be so wrapped up in the cleverness of their reasoning that they entirely miss the smoking gun, which has to be pointed out to them.

Compare Sherlock Can Read, Asymmetric Dilemma. See also Implausible Deniability. Has some similarity with Arson, Murder, and Jaywalking (or Bread, Eggs, Milk, Squick) but with weak arguments leading up to one strong one (and used as a deduction).

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Examples:

Anime and Manga

• The final sketch in Miss Kobayashi's Dragon Maid's sixth DVD special has Tohru do this while playing the part of Sherlock Holmes, pointing out that Lucoa just came out of the bath because of her wet hair, sweaty body, and complete lack of clothing.
• During the 4th Shinobi War in Naruto, Haku deduces that a bird flying above him is a fake as he knows that this particular species flies in pairs, but only during the winter. That makes their behavior suspicious. Also, he points out, it is releasing bright red signal smoke.

Comic Books

• Young Justice: In an issue where a mysterious new girl helps the team out during a fight, then disappears. When trying to figure out who she is, this exchange occurs:
  Robin: Her name's "Empress".
  Superboy: Wha...? How'd you figure that one out?
  Robin: It was through a series of clues and observations, with a few inferences thrown in for good measure. Oh, and there was also that...(points to the word "Empress" burned into the ground)

Fan Works

• RainbowDoubleDash's Lunaverse: In the non-canon side story Dinky & the Blanks, the Big Bad tries performing a Sherlock Scan on the Element Bearers, only for Trixie to quickly shut him down by pointing out anyone can see that Ditzy has strabismus, or that Lyra's a musician, or that Carrot Top is a farmer.
• In A Spartan in Westeros, Master Chief investigates Brandon Stark's fall from the Broken Tower. The next day, when Tyrion swings by to discuss the topic, he instantly fingers Cersei and Jaime as the culprits. An initially-flippant Tyrion challenges him to prove it, so the Spartan shows him the foot, hand and fingerprints they left behind, a hair from Cersei, and drops of mixed sexual fluids, finishing by telling Tyrion he has Brandon's direct statement.

Film - Live Action

• Parodied in Bullshot. Bullshot Crummond does a Sherlock Scan on a blade of grass and works out the kidnapping that's just occurred. One of his companions then points out the getaway vehicle left abandoned in the ditch nearby.
• Jimmy the Gent: Jimmy runs a scam where he recruits people to impersonate the long-lost heirs of rich folks who die intestate. His sidekick Lou has dug up a suitable fake heir, a woman who has the required identifying mark, a mole on her hip. Except that he got it wrong, as Jimmy explains.
  Jimmy: It wasn't a mole, it was a wart; it wasn't on her hip, it was on her shoulder; and and it wasn't a dame, it was a guy!
• Used in Miss Congeniality 2.
  Joel: And, may I say, I also recently went through a breakup.
  Gracie: I didn't go through a breakup.
  Joel: Puffy eyes, no sleep, irritable. And some of the other agents told me about it.
• The Naked Gun 2 1/2 has the lab break down the fibres, prints, DNA and dirt particles of the footprint and start to take a geological breakdown of the city. When the detective says they don't have that much time, they mention that the criminal also dropped his wallet by the curb and they may be able to use that as well. They have a habit of this, because in the third movie, they break down the origin and composition of the paper in a letter to find out who sent it, and when that fails, they then mention that the letterhead says "Statesville Prison" on it.
• In Night at the Museum, Larry tries to track down the caretakers who've fled with the Tablet and recruits Sacajawea to help, assuming she's a Scarily Competent Tracker. She goes outside, looks at the car tracks, and tells him the car tried to flee but spun out and crashed. When Larry asks her how she knows, she points at the wrecked car on the other side of the building.
• Parodied in the sort-of-comedy Smoke Signals:
  Thomas: Hey Victor! I'm sorry about your dad.
  Victor: How'd you hear about it?
  Thomas: I heard it on the wind. I heard it from the birds. I felt it in the sunlight. (Beat) And your mom was just in here, cryin'.
• True Romance has a protracted torture scene where mobster Don Vincenzo inquires about Clarence by torturing Clarence's father, who denies any knowledge until Don Vincenzo explains he knows when somebody lies, meticulously. Eventually all the explanation, clues, misinformation and time spent becomes immediately useless when the mobsters find Clarence's whereabout pinned on a piece of paper right there.
• Parodied in Van Helsing.
  Van Helsing: Whatever it is, it appears to be human. I'd say he's a size 17. Around 360 pounds. 8.5 to 9 feet tall. He has a bad gimp in his right leg and three copper teeth.
  Anna Valerious: How do you know he has copper teeth?
  Van Helsing: Because he's standing right behind you.

Literature

• Discworld:
  • In Thud!, the Lemony Narrator describes the architectural features that tell a visitor they've entered Ankh-Morpork's dwarf district, before adding that all the short people with beards and axes are a bit of a clue as well.
  • In Moving Pictures, Gaspode the Wonder Dog says that the mind-controlling magic of Holy Wood has got Dibbler "worse than anyone". When Victor asks how he can tell, Gaspode replies "Partly a'cos of subtle signs what you don't seem to be abler recognise, and partly a'cos he's actin' like a complete twerp, really."
• Ur-Example is probably found in The Hound of the Baskervilles where Holmes is able to deduce that Mortimer's dog must be a curly-haired spaniel...by seeing it coming up with its master.
• The Martian: Mark identifies a type of battery by a set of "subtle clues", the last of which is the label printed on it.
• In Quidditch Through the Ages, the fictional author describes the discovery of round metal balls believed to be Bludgers, and not cannonballs, based on very subtle indents made by Beaters' bats, the perfect symmetry only achievable by magic, and the fact that the balls started flying around trying to hit the discoverer when removed from their case.
• In the Rivers of London short story "The Domestic", Peter is investigating a woman whose flat has been occupied by an entity she believes to be the ghost of her husband. His narration notes that it doesn't quite behave the way ghosts normally do; that it appears as her husband did as a young man, while ghosts usually appear as they did on death; that the shoes don't match his Teddy Boy appearance; and that he doesn't remember the name of his mother. He then tells the woman (and the reader) that he checked before coming round, and her husband isn't even dead.
• In "Tomorrow Town", after a man is bludgeoned to death, detective Richard suspects that the master computer Big Thinks was responsible. His partner points out that, "[Big Thinks] hasn’t got sentience, a personality, a motive, or, most importantly, arms."

Live-Action TV

• In Arrested Development, Michael hooks up with a lawyer without realising she's blind until the morning after. The narrator notes that Michael "suddenly recalled some Non Sequiturs from the night before": In the first one she mentions having ocular retinoblastoma (he assumes it's "law talk"); in the second she mentions not being able to "see anyone ever" (he was talking about dating); and in the third one she just yells "I'm blind!" to which he responds "I'm wasted!"
• Barney Miller:
  • Barney played with this trope in one episode where Dietrich was investigating someone sending threatening letters to the Mayor of New York:
    Barney: So what do we have?
    Dietrich: So far...similar paper stock, the ink's the same...same return address.
    Barney: Why didn't you tell me that first?
    Dietrich: Dramatic effect.
  • Harris had caught a serial killer who was leaving bodies in garbage bags. He tells Barney how exhilarating it was following the clues, and "getting into the killer's mind".
    Barney: He left his wallet in one of the bags!
    Harris: Yeah, but I had to reach in and get it.
• In the season 3 premiere of The Big Bang Theory, Howard announces that Sheldon has run away providing the following evidence: he won't answer any calls, he quit his job, and he sent a text to Howard saying "I'm running away".
• Inverted in Brooklyn Nine-Nine when it is revealed to the audience that Captain Holt is gay, and has been out since the 1970s, yet the team of NYPD detectives now under his command missed all the clues. Some are more subtle, like certain mannerisms or the pride flag in his office. Others, like the framed article in his office with a picture of him and the headline "NYPD Appoints First Openly Gay Captain", less so.
• Surprisingly infrequent in Castle, where a complex series of deductions and circumstantial speculations lead to the killer. Since the police require proof beyond reasonable doubt, a last-minute smoking gun (or, sometimes, a cleverly extracted confession) is produced that seals the deal. But typically, solving the mystery points to an unexpected suspect or provides the clues necessary to establish probable cause so the police can get the evidence.
  • In "A Deadly Game", Castle and Beckett get the victim's lover, a Long Island housewife, to confess that she was having an affair. However, while a dramatic scene, the confession is unnecessary: they already have both the murder weapon and physical evidence putting the killer at the scene of the crime.
  • In "A Chill Runs Through Her Veins", Castle and Beckett identify the killer based on a chance conversation with a witness. They don't have any physical evidence or witnesses, so to close the case, the writers nicely have the killer volunteer a hypothetical confession so the viewer can feel satisfied that C&B have their man.
  • In "Famous Last Words", Castle must unravel the meaning of the lyrics for the victim's final hit single to solve the murder. Only then can he and Beckett confront the killer and clear the name of the innocent suspect. Except...the key physical evidence was texts sent on the innocent suspect's phone, which were far more explicit about what actually happened than the song, and which the police were already going through. This evidence on its own identified and proved who the killer was, so the business with the song was only important because Castle and Beckett hadn't read the texts yet. Castle even mentions, "It's a good thing we subpoenaed your phone records when I had this crazy lyric idea," even though the lyrics had nothing to do with getting the phone records in the first place. It was mentioned that they were coming before he started combing through lyrics.
• Community:
  • In the season 2 episode "Paradigms of Human Memory" (the non-recycling clip show), Abed deduces that Britta and Jeff are sleeping together from several subtle indications, and lastly: Abed saw them getting dressed together in a dormitory.
  • Parodied in "Aerodynamics of Gender," where Joshua the gardener makes some seemingly innocuous remarks to Troy and Jeff that turn out to have double meanings later... the swastika tattoo probably should have tipped them off.
    "It's going to be a maze!"
• Dollhouse has a light, comical version. When Caroline first meets Bennett in college, she guesses Bennett is a neuroscience major. Bennett is shocked she guessed that so easily and asks how she figured it out. Caroline says it's because Bennett is eating a tuna sandwich, and fish is brain food... and also because Bennett is carrying a large stack of neuroscience textbooks.
• Elementary: in the pilot episode, Sherlock performs his characteristic Sherlock Scan on Joan Watson, then explains his deductions. Watson says everything he says makes sense, except it doesn't explain how he knew her father had an affair. Sherlock says he Googled it, as "not everything is deducible."
• Parodied on the 1960s spy spoof Get Smart, where Max would begin to list a series of utterly nonsensical clues to the solution of an obvious mystery, and 99 would supply the smoking gun...which Max would then hastily claim was the last clue in his list. The joke is done in the movie Get Smart Again, but with Max listing off actual clues before providing the smoking gun himself.
• On Gotham, Ed and Lucius attempt to identify the rooftop where someone launched an RPG. When they arrive at one, Lucius announces they're at the right spot. Ed agrees, complimenting the two of them on figuring out that this rooftop is the only one that has the correct angle to have hit the target. Lucius then points out that the empty RPG case is still on the roof.
• How I Met Your Father: In "Reset Button" Sophie and Jesse end up at the apartment of a man they later realize is a bigoted Men's Right's Activist. Sophie comments that they should really have put it together sooner, and we get three flashbacks: the first is of him commenting that Jesse (a handsome white man) is the perfect American male, the second is of him saying "Women, am I right?" and the third is of him straight-up telling Sophie he's an MRA leader.
• In "Mr. Monk and the Class Reunion", where Randy investigates a suspect whose motive to kill someone would have probably been the victim busting him for drugs which barred him from participating in the Olympics. However…
  Disher: Captain, I tracked down Kalimarakis; I don't think he's our guy. Number one, it turns out he was allowed to join the Olympic swim team as an alternate; he got a waiver.
  Stottlemeyer: So there's no motive.
  Disher: Right. Number two, he's dead. He died in 1995. And number three, he moved to Europe in the late eighties. So there's no record of him ever returning to the United States...
  Stottlemeyer: Randy, Randy, excuse me, sorry to interrupt you, but what was number two again?
• Sherlock:
  • In the third episode, "The Great Game", Holmes deduces that Molly's new boyfriend Jim is gay because of vague traces of make-up, subtle hints in his clothing, and slipping Sherlock his phone number. Jim helpfully provides the Smoking Gun himself so that Sherlock will miss the fact that his last name is Moriarty.
  • Played with in "The Blind Banker". Sherlock deduces that a banker has flown around the world twice very recently, and explains that he noticed his watch was set to the correct time, but the wrong date. He then adds that also, the banker's secretary told him explicitly. Watson later reveals, however, that the secretary told him no such thing, and Sherlock really did deduce it from the watch alone.
• There's a short The Two Ronnies sketch in which Ronnie Barker plays a detective. He is given a pound note and proclaims that it's a counterfeit. When asked how he knew, he gives a series of very subtle clues that only someone with a trained eye would have been able to spot (like the letters being just a fraction of an inch lower than they should be, or the shading getting dark too fast)...then turns it over and points out that it says "Bank of Toyland" on the back.
• Used in the Veep season 2 episode "The Vic Allen Dinner":
  Sue: You think I had a job interview?
  Dan: I know you had a job interview.
  Sue: How, Sherlock?
  Dan: Simple makeup, higher neckline. Flats don't go with that dress, which means you probably have heels in your bag. Coffee from corner bakery implying you were at one of the lobbying shops on 18th.
  Mike: I love this stuff.
  Dan: That and somebody called your extension to make sure you had the right address.

Radio

• In the Grand Finale of Cabin Pressure, Carolyn describes a picture in her office as being of a dogfight between two Spitfires. Martin points out one of the planes is not a Spitfire, citing the wings, fuselage, markings, and the fact that Spitfires didn't fight each other.

Video Games

• Danganronpa: Trigger Happy Havoc: Clues from the first case include paint taken from a display sword, an unscrewed doorknob, and a locked incinerator room... and the victim wrote their killer's name behind them in blood. To be fair to the characters for not getting the culprit immediately, it was written upside-down and in English, so they initially assumed it was a number. This has, however, led to a lot of very confused English-speaking fans wondering why Makoto is so stumped when it's obvious from the start that the killer is Leon.
• GreedFall: During the evidence gathering portion of the trial against Dr. Asili, De Sardet lists out evidence to help the prosecution, which will win so long as they provide the black powder that is a powedered version of the Malichor used to poison Constantin and attempt to poison De Sardet. However, they can also list off every other piece of evidence and witness testimony prior to the black powder, leading to the amazing list of: Asili running a laboratory, employing other researchers to help his research, Aphra leaving due to his research methods, Asili kidnapping natives for his research, and finally, the black powder used to poison Constantin and De Sardet.
• In Grim Fandango, Mercedes asks Manny how he could be so sure that she had led a good life. He replies: "I can see it in your face". Then, a second later: "And in your file here".
• A case in Phoenix Wright: Ace Attorney: Justice For All has the rather pretentious witness Wellington claim that he knew a victim was a police officer because of his shoddy, do-it-yourself hairstyle, the way he tied his tie, and his basic-looking shoes. That, and the policeman's uniform he was wearing.
  Phoenix: (Shouldn't that statement have come first?!)
• In Vampire: The Masquerade - Bloodlines, Adventurer Archaeologist Beckett manages to pinpoint the local headquarters of a secret society of vampire hunters by examining the hue and texture of a pinch of beach sand, the distinct yet subtle aroma of a whiff of incense...and the testimony of a vampire hunter dangled over a balcony by his ankle. (Beckett is well known for having a dry wit.)
• In Virtue's Last Reward, Luna's innocence is proven this way during the Summation Gathering. Sigma first explains how he thinks everyone involved had died, while adding clues that support his theories, and when he's done, Luna insists that it's just a theory and doesn't prove she is innocent. Sigma then drops the final piece of evidence: Luna couldn't have killed anyone, because as an android, she's Three Laws-Compliant.

Webcomics

• Dresden Codak:
  • After Kim is the victim of a Satchel Switcheroo, Vonnie explains how she ran the contents of the thief's bag through several departments of the city's Vast Bureaucracy and finally managed to narrow down his identity... while a caption points out that one of said contents was a teacher's ID card with his name and address on it. This kind of myopia is entirely in keeping with Nephilopolis' culture of preferring by-the-numbers scientific literature review to direct observation of anything.
  • Yvonne does this again in a later strip while investigating the disappearance of Asmodea:
    "While reviewing 437 cases, I noticed several irregularities in the alleged abduction of Asmodea Harthrow. The Dept. of Surveillance footage shows her never once leaving her apartment that night, 26 blocks from the party in question. Even her own Dept. of Distraction shows she hasn't missed a day of work since the incident. Also she's literally right here — [gestures to where Asmodea's been sitting Behind the Black all along] — I found her downtown buying soap."
• Flaky Pastry: When Zintiel and Marelle discover that Nitrine is gone, the Alt Text implies an exchange between them with Marelle undercutting Zintiel's deduction by pointing out the obvious.
  She can't have been gone long... the gum from her posters is still fresh - Ahem. Also we both saw her yesterday.
• An early Leftover Soup page has Jamie deducing Ellen is a Tauren World of Warcraft player. Her fridge magnets spell "Fuck the Alliance," her oven mitts and shakers have a cow pattern, and she hadn't logged out.
• The Order of the Stick:
  • Used in this strip when Tarquin explains the reasons why he is sure Nale hasn't left the city after his latest scheme fell through: because Nale is a cautious planner and thus wouldn't leave the city without replacements for the men he lost, because Nale has a massive ego and thus wouldn't leave until he knew what Elan and Tarquin had to say about his stunt... and because Tarquin is wearing a ring of True Seeing and thus can see the invisible Nale standing right next to them. Cue massive Oh, Crap! from the latter.
  • In a later strip, Elan asks Roy why they couldn't use Banjo the Clown, the Deity of Human Origin he created, to break a deadlock between all the gods of the world voting whether or not to destroy the planet. Roy offers three reasons: Banjo is not actually recognized as part of any existing pantheon, the voting requires a high priest capable of casting a rather powerful spell to channel their god, when the only worshipper of Banjo is a mid-level bard, and third, Banjo is a hand puppet. Before hearing the last reason, Elan actually looks horrified that Roy seemingly took his suggestion entirely seriously and may have even considered it himself.

Western Animation

• In the Arthur episode "Is That Kosher?", Francine complains about having to fast for Yom Kippur, and her Bubbe deduces that she broke her fast by eating some of Arthur's pizza. When Francine asks her Bubbe how she knew, she responds, "Bubbes know these things. Plus, there's a mushroom on your shirt."
• Mr. Peanutbutter, of all people, manages to do this twice in Bojack Horseman:
  • In "Our A-Story is a D-Story", he deduces that BoJack stole the D from the Hollywood sign by following a series of clues, using deduction, puzzle-solving skills, and forensics...and the fact that BoJack left him a drunk voicemail saying that he did it.
  • Then, in "Let's Find Out", he confronts BoJack about kissing Diane after their engagement. He claims to have found this out via security camera footage along the freeway, talking to his friends on the highway patrol, and she told him.
• Chip 'n Dale: Rescue Rangers: In "It's A Bird, It's Insane, It's Dale!", the clue is a brochure from a travel agency. Gadget performs a chemical test on a scrap of the brochure, and triumphantly announces, "it's made out of paper!", then adds the name and address of the agency.
  Monty: Wow, that's some test, Gadget luv!
  Gadget: Well, actually, the name and address are printed on the bottom of the brochure.
• In the "Take My Life, Please" episode of The Life and Times of Juniper Lee, after June relinquishes her title to Ashley:
  Cletus: June! We got big trouble!
  Gus: A Racatan is barbecuing his way through the trolls' tree farm!
  June: Ah, Ashley will take care of it.
  Cletus:: A fifth-level incubus is about to release a demon from an interdimensional portal!
  June: Oh, that will take a week, she'll get to it. It's not a problem.
  Gus: And then there's the fuster troll.
  June: Okay, okay, now you guys are just acting girly. All they do is eat dandelions.
  Cletus: Ashley fed it a cookie.
  June: SHE FED IT A COOKIE?! You can't feed fuster trolls human food, or they -
  Gus: - grow thirty feet tall and everything they touch turns to stone?
  June: Uh! You guys could have mentioned that first!!
• In the My Little Pony: Friendship Is Magic episode "Rarity Investigates", Rarity accuses Wind Rider of framing Rainbow Dash based mostly on circumstantial evidence. Rarity admits later that she didn't have much of a case until she revealed the Smoking Gun, which was a stain linking him to a Delicious Distraction.
• Recess: In "The First Picture Show," TJ knows Principal Prickly is a Señor Fusion fan because he calls the hero by his shortened name of Fusion (like so many fans), he has a stack of comics in his office (which Prickly tries to claim were confiscated), and he has a fan card club with his name on it.
• She-Ra and the Princesses of Power: In "Reunion", Adora tracks Bow using broken twigs, sap on the trees, and his incredibly distinctive and obvious bootprints.
• The Simpsons:
  • Used in episode "Homer the Vigilante":
    Abe: He was right under my nose the whole time. He lives in my retirement home. His name is Malloy.
    Lisa: Wow! How'd you track him down, Grampa?
    Abe: Good question! [a flashback shows Abe stumbling to the floor] On one of my frequent trips to the ground, I noticed Malloy wore sneakers... for sneaking. My next clue came yesterday at the museum. We felt slighted by your age-bashing, and started home. Malloy said, "I'll catch up with you." [Malloy throws a grappling hook at the museum roof and starts climbing] I couldn't quite put my finger on it. There was something strange about the way he walked -- much more vertical than usual. And finally, Malloy, unlike most retired people, has the world's largest cubic zirconia on his coffee table.
  • In "Sunday, Cruddy Sunday", Wally's Super Bowl tickets are revealed to be fakes because the hologram is missing, there's no such team as the Spungos, and they seem to be printed on some kind of cracker. Which is still edible.
• The South Park episode "Not Without My Anus" opens with Terrance on trial for the murder of a Dr. O'Dwyer. The prosecutor, Scott, provides as evidence a piece of Terrance's shirt, the hammer used in the murder, and a haiku Terrance penned:^note Despite the evidence, Terrance walks, because of Phillip's statement that he "likes puppies and hates mean things".
  Dr O'Dwyer
  Time to have your head smashed in
  with my new hammer.
• In Teenage Mutant Ninja Turtles (2012), Mikey asks Donatello how he knew a Kraang substance was explosive. Donny gives a technobabble explanation about its molecular structure, which goes in one ear and out the other, before concluding by pointing to a Danger: Explosive sign on it.

Real Life

• There is a quite famous anecdote about Doctor Joseph Bell, who was supposedly the real life inspiration for Sherlock Holmes. When presented with a patient in front of his students he asked them to use deduction for finding the patient's problem. When nobody found it, he explained the process thus: use clues to make an assumption (red nose and pimples that would suggest alcoholism) and then support that theory with hard evidence (whereupon he pointed at a bottle of brandy in the patient's pocket).
• In The Rush From Judgment, the author, a doctor, spoke of a conversation with a patient from the slums who was shocked when he deduced that her boyfriend was choking her.
  "And, of course, he sometimes grabs you round the throat and squeezes and tries to strangle you?" I ask.
  "How did you know, doctor?"
  "Because I've heard it practically every day [from other patients in similar situations] for the last seven years. And you have marks on your neck."

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