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Conviction by Contradiction

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"You don't like the way I phrased an answer. What kind of evidence is that?"
The guy who did it, Monk, "Mr. Monk Fights City Hall"

The classic whodunit challenges the viewer to solve the crime along with the detective. Since the viewer isn't a professional, the crime has to be set up so that the solution doesn't rely on skills only a licensed criminologist would have. These mysteries often work by reducing the crime to a logic puzzle: you solve the mystery by finding the fact that doesn't fit.

The problem with this is the "solution" at the back of the book doesn't give the perp a chance to offer a perfectly reasonable explanation.

So, for example, let's say the police are investigating a murder, and Bob is their lead suspect. Bob says that at the time of the murder he was attending a party and his friend Alice was there with him. But wait! It turns out that Alice was on vacation in a foreign country at the time, so she couldn't have attended the party with Bob.

In fiction, this is usually enough to prove Bob's guilt, or at least cast serious suspicion on Bob. In the real world, of course, this does not in any way mean that Bob committed murder. Maybe Bob still attended the party, but it was with his friend Charlie, not Alice. Maybe the party was on a different night, or there was a second party that Alice did attend with Bob, and Bob just misremembered. Maybe he attended the party with a different person named Alice, and for whatever reason answered the question only mentioning the first name. Maybe Bob was lying because he was doing something embarrassing that still wasn't, you know, murder.

Real crimes aren't logic puzzles and mere factual inconsistencies aren't a substitute for hard evidence. Poking holes in a suspect's story might push a jury towards the edge, but it's not going to convince them by itself. You might be able to Pull the Thread, but on its own, proving that the suspect lied about something doesn't prove he committed the crime (especially if he has a Big Secret). At best, this kind of logic game can be used during Perp Sweating to get a confession. At worst, Detective Brown will arrest the perp immediately, but Perry Mason wouldn't even break a sweat getting an acquittal from that.

More realistic examples focus on the investigative side, where the contradiction satisfies the significantly lower standard of proof required to arrest someone and investigate them further, rather than the much higher standard to convict them, or on non-legal contexts where the solution is just about swaying people's opinions rather than meeting any rigorous standard of proof. Some stories handwave this issue by having the contradiction lead to further investigation and the discovery of more concrete evidence. In stories involving teenage perpetrators, the crimes are often rather minor and the solution has them immediately confess when the contradiction is pointed out; this is somewhat less plausible against adult suspects, but even in Real Life, plenty of people don't know their rights or make mistakes when pressed.

Note that in modern legal systems, it is far more realistic to have this trope derail a prosecution, both because the defense only needs to introduce the possibility of reasonable doubt (which a contradiction in a witness statement often accomplishes), and because the prosecution has the burden of having to prove their case. A contradiction in the defense's alibi doesn't necessarily prove them guilty if the prosecution otherwise failed to make its case; but for the prosecution, even an entirely innocent mistake in a key witness statement can call the credibility of the entire statement into question and cause the case to collapse.

See also Conviction by Counterfactual Clue, which is when the "flaw" found to prove the suspect's guilt is simply erroneous. This overlaps with Hyper-Awareness — sometimes it's just hyper-awareness taken too far, to the point of noticing details that logically shouldn't even be noteworthy. Can lead to a minor Inferred Holocaust, if logic dictates that the supposedly happy ending will lead to either a guilty character escaping or an innocent one being convicted. These types of inferences often run afoul of Hanlon's Razor, blaming every flaw or contradiction on lies and conspiracy rather than, say, faulty memory or panic.

Compare I Never Said It Was Poison, where the suspect demonstrates knowledge of a detail or two they shouldn't.

This gets particularly egregious when the story contains perfectly good alternative clues, but the flimsy one was chosen as The Clue.


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    Encyclopedia Brown 
This has happened so often in Encyclopedia Brown shorts that the former Trope Name was "Bugs Meany is Gonna Walk".
  • Book 1, Chapter 5 ("The Case of the Bank Robber"): A blind man is the only witness to a crime; a perp fleeing the scene with a bag of cash crashed into him, and it is thought that the man might have felt his face well enough to identify him if he felt it again. Turns out the blind man is not blind and was in on it the whole time: he swapped bags with the thief when they collided. How does Encyclopedia prove this? When he visited the man in his hotel room, the lights were on and there was a newspaper on the table despite the man claiming he hadn't had visitors in "a long time". Because no hotel in the world offers complimentary newspapers that they put in your room. And they never have the lights on when you arrive. And a blind man would totally notice if they were on, and turn them off. This is a lesser example, however. Once Brown figures out what happened getting a doctor to confirm that the guy can see shouldn't be too hard. Overlaps with Conviction by Counterfactual Clue since most blind people aren't completely blind and it is entirely possible for one to leave the lights on and read a newspaper.
  • Book 1, Chapter 7 ("The Case of the Happy Nephew"): A ex-convict is accused of robbing a bake shop, but he claims he was driving all day. Encyclopedia realizes he's wrong when he sees the convict's barefoot nephew happily playing on the hood of his car: if he had been driving all day, the hood would've been hot and the nephew would be crying in pain.
  • Book 1, Chapter 9 ("The Case of the Missing Roller Skates"): Combining with "I Never Said It Was Poison", Encyclopedia is at the dentist's and has his roller skates stolen. The perp manages to identify himself because he never even heard of him (Dr. Vivian) until Brown mentioned him, and he wasn't at the dentist's because "I had a sprained wrist, not a toothache". Because he couldn't have found out that Vivian was a dentist through other means (such as being close enough to notice that this is a dentist's office), or simply assumed "Vivian" was male since Vivian is a gender-neutral name. (In fact, it's only been seen as a feminine name since around the '40s or '50s.)
  • Book 2, Chapter 7 ("The Case of the Wounded Toe"): A boy gets injured in the foot by an unknown suspect. Another boy is asked to bring a spare shoe for the injured party. Brown deduces the other boy is the perp because he brought the right shoe for the injured foot without asking beforehand which shoe to bring. While common sense might suggest to the boy to think about which foot would need the shoe, he still had a 1 in 2 chance of getting the right shoe if it didn't occur to him right at that moment to ask and, although the wrong shoe might not fit comfortably, it could still fit his foot if the size allows for enough space. Encyclopedia does point out, however, that if the boy didn't know which shoe to bring, he would likely have brought back both shoes. The boy brought back only the one, however, which made Encyclopedia suspicious.
  • Book 2, Chapter 8 ("The Case of Excalibur"): A "witness" trying to frame a boy for the theft of a pocket knife claims the boy took the knife with his right hand and put it in his pocket while running away. He is found innocent because he has a cast on his left hand and the knife was found in his left pants pocket (planted there by the "witness") and (according to the answers section at least) it's impossible to put a pocket knife in your left pants pocket with your right hand while running. Leaving aside that Encyclopedia was assuming an impossibility out of a difficult and highly improbable physical stunt, the mere likelihood of him putting the knife in his left pocket after he'd stopped running never occurred to him.
  • Book 3, Chapter 3 ("The Case of Bugs's Kidnapping"): At least one time the series used this trope absolutely correctly. Bugs claims to have been kidnapped at Encyclopedia's behest (how a 5th-grader was able to hire and control adult Mooks is never discussed). He describes being imprisoned in a small room and attempts to escape by removing the pins from the door hinges, but they are on the other side of the door. Then he tries to wait to the side of the door and jump his kidnappers when they come in, but the door opens into his face, foiling the attack. Standard house doors cannot open away from their hinges, only toward them.
  • Book 4, Chapter 8 ("The Case of The Blueberry Pies"): Encyclopedia is watching an pie eating contest combined with a foot race. When one of the Thompsons twins is declared the winner, he instantly knew they cheated and swapped places when the twin showed off a beautiful clean smile. Anyone who had scarfed down two blueberry pies would've had the teeth stained.
  • Encyclopedia Brown liked solutions where the answer hinged on an American city having the same name as a foreign place that was generally more famous, for example Paris, Texas. This isn't usually conviction by contradiction, but became a case of it in the answer to Book 6, Chapter 5 ("The Case of the Wanted Man"), which involved an American city called Palestine, where Encyclopedia declared that it had to be the American city because "nobody calls the real one Palestine anymore." Apparently in Encyclopedia Brown's world, Palestinians don't exist. (later political controversies notwithstanding, prior to the 1967 War the non-existence of Palestine was indeed generally considered a non-controversial matter.)
  • Book 6, Chapter 6 ("The Case of the Angry Cook"): A man accused of committing a robbery is being interrogated in the crime scene and claims he has never been there before. Shortly afterward, he says, "When you brought me back here, did I resist?" to the police officer. Since he couldn't be brought back if he had never been there before, the man is guilty. First of all, the term "back" doesn't have to mean "return." It can simply indicate distance or location, shown in common phrases such as, "He's from back east." You can also say you're taking someone "back" somewhere if you've already been there. The all-too-common example would be asking a stranger, "Want to go back to my place?"
  • Book 7, Chapter 10 ("The Case of the Foot Warmer"): A young inventor named Melvin is accused of smuggling two BB rifles out of a toy shop, but the kid claims he was just wearing his new invention at the time. Encyclopedia realizes the inventor is lying when the toy shop owner remembers Melvin bent down to pick up a baby: Melvin's invention prevented him from bending down, so he couldn't have been wearing the foot warmer at the time.
  • Book 8, Chapter 9 ("The Case of the Two-Dollar Bill"): The perp tells someone he's hidden a $2 bill between an odd and even page of a book that are normally on opposite sides of a leaf if the book is read left to right. It might be possible that the book had a typo, breaks the tradition, had its pages printed out of order, or the perp simply misremembered the book pages.
  • Book 9, Chapter 4 ("The Case of the Headless Runner"): The perp claimed to have been awoken by a thunderclap, then saw the crime during a lightning flash. E Brown knew that the perp was lying since in real life, thunder follows lightning, not the other way around. Of course, it's inconceivable that there would be more than one lightning flash during the course of a thunderstorm.
  • Book 9, Chapter 6 ("The Case of the Tooth Puller"): A carnival tent gets upended, and the take is stolen in the confusion. When Encyclopedia studies the injuries of the performers, he suspects the magician; the reason? He's wearing a short-sleeved outfit, and "all magicians wear long sleeves to hide things in." This example is also listed under Conviction by Counterfactual Clue.
  • Book 10, Chapter 3 ("The Case of the Two-Timers"): A perp who's trying to frame Encyclopedia for claiming ownership of the town clock and charging people to use it to set their watches is "proved" as a liar because he used his left hand to set his own watch, because of the "fact" that when you set your watch with your left hand, you're holding it upside down. (Because it's impossible that a person could simply be more comfortable using their left hand, and compensate for it when setting their watch, or that one could buy left-handed watches specifically to avoid this problem, and ignoring that watch faces are quite easy to read upside down.)
  • Book 12, Chapter 1 ("The Case of the Dead Eagles"): The perp claims to have seen something by moonlight on a night when there was no moon. It's entirely possible that the perp saw the incident by another ambient source of light and simply assumed it was moonlight. Interestingly, Abraham Lincoln got an acquittal in a case in exactly this manner, though in his case it was used to show that, without moonlight, it would have been impossible to see something 150 ft away at night in 1858.
  • Book 12, Chapter 6 ("The Case of the Old Calendars"): A note about who was supposed to receive their share of thirteen calendars couldn't have been written by a math teacher because it says "divide the calendars by 1/2", which would actually be multiplying by 2 or an impossible division. Math teachers apparently never make mistakes in grammar or use common English-language phrasing fallacies outside of the context of the classroom, and never write a note when tired.
  • Book 13, Chapter 2 ("The Case of the Hidden Penny"): A stolen rare coin is found inside Bugs Meany's hot dog. How did Encyclopedia know where to find it? Because he saw Bugs spread mustard on top of the sauerkraut, and "no one who likes hot dogs does that." Admittedly, it is a pretty messy way to go about things (similar to trying to spread peanut butter on top of jelly), but c'mon. Interestingly, the story effectively admits Bugs would have walked if he'd been willing to finish his hot dog, and presumably swallow the coin in the process. Also a case of Technology Marches On, as a modern reader would expect the mustard to come out of a squeeze bottle and be easier to have on top than the sauerkraut. Plus, who's to say Bugs hadn't just overlooked the mustard jar, or that someone else was hogging it when he first started applying his hot dog toppings? For that matter, how hard would it have been for him to just put the bite of hot dog in his mouth and stick the penny under his tongue or the bottom of his cheek?
  • Book 14, Chapter 1 ("The Case of the Giant Mousetrap"): A perp claims to have been on the bottom floor of a building when the crime was committed, yet when he went to the elevator, he pressed the "up button." Encyclopedia deduces that the perp was probably not on the very bottom floor, because the perp wouldn't have had to distinguish the button as the "up button" because there wouldn't have been a "down button." Of course, an "up button" is always an "up button" whether or not there's a "down button" along with it. The actual name for them is "call button", but it's rarely used outside of technical and legal documentation. Besides, plenty of call buttons still have the appropriate arrow on them even when they're on the top and bottom floors.
  • Book 14, Chapter 7 ("The Case of the Marvelous Egg"): A local con man claims to have bred chickens that can lay square eggs. He comes up with a lame handwave as to why he simply can't show them, and claims instead that he'll stage a publicity stunt by having the skydiver standing with him jump holding one in a box only to have it still intact afterwards but needs money for promotion. Encyclopedia calls him out because the skydiver is wearing only one parachute, and all jump with two in case one fails...because there's no chance that someone might wear something different to a publicity event than during actual skydiving. Granted the con man does describe his accomplice as dressed "ready to jump", but considering the whole absurdity of the situation (the convenient excuse as to why he can't just show the eggs, the fact that a square probably would be crushed if held by a skydiver anyway, why such a stunt would even be necessary to promote square eggs, and of course, what the hell besides novelty value is the benefit of square eggs anyway?) it seems kind of silly that Encyclopedia quibbles over such a minor technicality. The "Solution" page at the end of the book even admits that had Wiggins not embellished his con by bringing his friend along, Encyclopedia would have had nothing to use against him and he could've successfully screwed the kids out of their money.
  • Book 14, Chapter 10 ("The Case of the Thermos Bottle"): Bugs Meany holds a raffle drawing at a fair for a baseball glove and has one of his friends reach around for another associate's balls in the big container of ping-pong balls. Encyclopedia discovers he was cheating by noticing that Bugs drank a canned soda when he was carrying around a thermos, thus meaning he put the ball in the freezer, then took it to the fairgrounds in the thermos so the associate would just have to feel around for a frozen ball. It's entirely possible that Bugs simply didn't want whatever was in his thermos at that particular moment or was saving it for later. Or that he'd already emptied his thermos, and found himself wanting another drink.
  • Book 15, Chapter 1 ("The Case of the Supermarket Shopper"): The perp buys time to rob his victim's house by asking the victim to add four tubes of toothpaste to his supermarket order of seven items. This required the victim to check out in a regular shopping lane instead of the 10-items-or-less express lane, which otherwise would have allowed him to return in time to see his house being robbed. Brown figures it out because the perp was the last of the victim's friends to ask for items, and his order was too plainly designed to surpass the Express Lane Limit. Of course, the fact that the perp counted on both the victim and grocery staff to obey the letter of the express lane rules and for the express lane line to be open and available at the same time he was at the store pretty much means he deserved to get caught. Even Donald Sobol (the author) seemed to realize that this one was flimsy; Mrs. Brown specifically mentions that the store is notorious for demanding exactly ten items for the express lane. That doesn't quite fix the problems (again, the lane might not have been open in the first place), but points for trying.
  • Book 15, Chapter 10 ("The Case of the Marathon Runner"): A case had a kid that finished last in a race correctly identify a song being played at a theater along the race route as "The Eyes of Texas" (The University of Texas one) rather than the original tune it was adapted from, "I've Been Working on the Railroad," "proving" she stopped to ensure that she would finish last. Even assuming it was a lyricless version (which would be a dead giveaway), given it's the University's school song anyone who knows "The Eyes of Texas" is likely a graduate or a fan of their sports team in the first place, and the song is only a minute long anyway.
  • Book 16, Chapter 2 ("The Case of the Battle Cries"): A boy blows his fake alibi by tracing a shirt pocket on the wrong side of his chest. This is perfectly understandable since everyone is accustomed to seeing images of themselves in the mirror, where left and right are flipped.
  • Book 16, Chapter 7 ("The Case of the Hard-luck Boy"): A contest is held in which contestants complete a quiz for 3 secret prizes for 1st, 2nd, and 3rd place. The first-place winner receives the best prize: a watch, which he discovers has been broken. The theory of the crime is one of the contestants secretly examined the prizes and played with the watch and broke it. The culprit turns out to be the 2nd place girl that purposely missed a question she should have gotten right: "Name a word that has three double-letters." The girl referred to herself as a "bookkeeper". This doesn't account for the possibility that the word simply slipped her mind at that exact moment. Or perhaps she can't spell it — thinks it only has one k, for example, or thinks it's two words. Or perhaps she hyphenates the word, as "book-keeper" (a valid, if rather old, spelling), splitting one of the double letters.
  • Book 16, Chapter 10 ("The Case of the Mysterious Handprints"): Two precious ivory bookends belonging to a former circus owner are stolen when two of the man's friends are visiting. Encyclopedia and his father find strange handprints on the beach near the circus owner's house, and so suspicion falls on one of the visitors, a crippled acrobat, because the only way he could have walked was on his hands. Encyclopedia, however, insists that the thief is in fact the other visitor, a former bareback rider, because she said her leather gloves were missing, and "no visitor brings leather gloves to Idaville in the summer." (Again, an assumption of concrete fact out of a generalization, but even so she could have brought the gloves for a legitimate reason like playing golf, as driving gloves, or even riding a horse. Or maybe she packed them by accident.) The missing bookends being found wrapped in the woman's blouse is much more of a clue, but still not definitive in itself.
  • Book 17, Chapter 1 ("The Case of the Masked Robber"): Encyclopedia's dad described a case to him after the fact that involved a professional tennis instructor who reported that a set of ivory screens had been stolen that morning. He saw the thief's face; it could be either of two identical twins — one who worked as a cashier and one who played tennis. Encyclopedia figures out that the victim was just lying so he could get insurance money for the screens, because the crook was wearing a T-shirt, and if the tennis player had been the culprit, one arm would be more developed, while equal arms would incriminate the cashier. This assumes that the instructor had the presence of mind to make such an astute observation, and also assumes the untrue "fact" that all tennis players have asymmetrical arms.
  • Book 17, Chapter 6 ("The Case of the Painting Contest"): A sailor wins a painting contest open only to amateurs. He is called out as a professional painter pretending to be a sailor because he failed to do the research on nautical terminology: he used terms like "left" or "right" when describing a boat he was painting rather than the nautical terms like "port" or "starboard", as well as the redundant phrase "knots per hour"note , mistakes that no one remotely familiar with sailing would have made regardless of their expertise level. However, while "he's a professional painter trying to pass as an amateur" is the most likely explanation for the masquerade and was probably sufficient grounds on its face to get him disqualified, he might have had other reasons for the pretense and it's not ironclad evidence he's an actual professional.
  • Book 18, Chapter 2 ("The Case of the Teacup"): Bugs steals an antique teacup. When Encyclopedia confronts him about it, Bugs claims that it was a prized cup from the owner of a Chinese restaurant that has since gone out of business. Encyclopedia deduces that he's lying by noticing that the cup has a handle, which Chinese teacups do not have. (Because it's impossible for a Chinese guy to like American mugs, and of course, with globalisation Chinese teacups with handles do exist now.)
  • Book 18, Chapter 9 ("The Case of the Disgusting Sneakers"): One story had a girl having one of her sneakers stolen from her before a sneaker contest was held. The thief was identified because she said to another person that the girl had the sneaker stolen from her "while clipping her toenails", even though all the girl said was that she was "clipping her nails". And only the thief would know that she had been clipping her toenails and not her fingernails (even though if someone said she had her sneaker stolen while clipping her nails before a contest involving feet, most would immediately assume the nails WERE toenails, not fingernails.) There's no reason to take your shoes off to clip your fingernails, and it's a safe bet a person would notice someone stealing shoes that they were wearing at the time, making it even less of a stretch to assume that toenails were meant.
  • Book 20, Chapter 6 ("The Case of Pablo's Nose"): A perp is accused of stealing something that belonged to Encyclopedia's client and riding away on her bicycle. She claims that she hasn't ridden her bike all summer, before she takes it out of storage and starts showing off on it. Encyclopedia declares that she's lying because if she hadn't ridden the bicycle like she claimed, the tires would have gone flat. (Because it's impossible that the girl or her parents could have kept the tires inflated in case she ever decided she wanted to go for a bike ride.)
  • Book 22, Chapter 4 ("The Case of the Roman-Numeral Robber"): The perp claims to have been out of town during the crime, but knows details about some contemporaneous local event (because, clearly, he never talks to anyone about local events or reads newspapers).

  • In the 1960s, Charlie Chan played with this trope to sell Volkswagens. In a TV ad, Charlie and company are gathered around the hospital bed of the perp he just fingered, and he explains how the seemingly obvious alibi—the man has his left leg and right arm in casts, therefore he could not have driven the stolen car—is no good after all. This Volkswagen has a new-fangled "automatic stick-shift transmission", so there was no need to work the clutch and shifter.
    Charlie: "In conclusion, only thing evil man like Motley really need was far better alibi."

    Alternate Reality Games 
  • Perplex City: The card "Alibi" pegs the maid as a murderer because she said she was getting the mail at the time of the crime—a Sunday. (Of course, no one ever picks up Saturday's mail on Sunday.)

    Anime & Manga 
  • Case Closed: Played with. The detectives will sometimes find an inconsistency and then ask the culprit to explain. Not using this as specific evidence that they are guilty, but to force them to come clean. A notable example of forcing the culprit to come clean after being caught in a misstep is in one case in which a person is murdered in a cabin during a blizzard. The culprit's alibi is that they were buying snacks, but did not buy ice cream because they were "sold out". And why would anyone be sold out of ice cream in a blizzard? The culprit could have just as easily lied and said she didn't get ice cream because it would melt due to it being a blizzard (thus requiring the car to have the heat on, and the trip back being slowed). There's also a chance the store was out of ice cream because they didn't order any since winter was coming up. There's also a chance they were actually sold out - maybe it was a particular brand or flavour of ice cream, or maybe the store didn't order any more (because it was winter).
  • Guilty Crown: Inori's Void is a sword. Hardly holds together as part of the Pacifist she is (her mellow temper and submissiveness, the lyrics in her songs, etc), foreshadowing her soul to be a replica of Mana's. Note, however, that her 'pacifism' does not extend to not shooting GHQ personnel in the face, or not beating up her schoolmates when they try to mess with her.
  • Shibatora: Kuma, in the Angel storyline. Not actually conviction, but arrest by contradiction (the protagonists being police rather than lawyers.) However, once he's kept from walking, the case against him builds easily.

    Comic Books 
  • Archie Comics:
    • Inverted in one story. When Betty is framed for academic plagiarism, Archie investigates the evidence against her and points out the flaws in it that prove her innocence. He then offers actual physical evidence that proves that she was framed by a jealous rival.
    • Inverted again in another story where Archie accidentally spills paint remover on an 1870 Frederick Church painting that Mr. Lodge buys from an art dealer. Mr. Lodge is predictably upset, but then Archie wipes away more paint and finds the signature "Picasso". Mr. Lodge is suddenly thrilled, thinking that he's actually discovered a long-lost painting by Pablo Picasso, but then his butler Smithers reminds him that Picasso was born after 1870, the date when Church supposedly painted his picture. When it dawns on Mr. Lodge that Church couldn't have painted over Picasso's original painting if Picasso wasn't even born yet, he realizes that he's being conned. Mr. Lodge then takes back his check from the crooked art dealer and gets Smithers to help him literally throw the dealer out of the house.
    • Yet another story had Archie and Jughead housesitting for Mr. Lodge and Veronica while they went on a family trip. A crooked art dealer and one of Mr. Lodge's security guards use the opportunity to steal Mr. Lodge's collection of priceless paintings and replace them with forgeries while trashing the Lodge house to make it look like Archie and Jughead threw a Wild Teen Party and distract Mr. Lodge. When he comes home, Mr. Lodge falls for it and is furious with Archie and Jughead, but then Archie realizes that the paintings weren't at all damaged by the "party". He convinces Mr. Lodge that they were hung after the wrecking was done, and proves that they're fakes. Archie and Jughead then direct the police to the art gallery, where they find Mr. Lodge's real paintings. Archie explains that the crooked art dealer couldn't bear to damage his expert forgeries and ended up tipping Archie off to the fact that they were fakes, which makes this a case of Hoist by His Own Petard.
  • The Bruce Wayne: Fugitive arc toyed with this; every time one of the bat-family found some piece of evidence indicating Bruce had been framed for Vesper's murder, someone would pipe up with the obvious: Bruce was more than capable of forging/planting that very same evidence to make them think he'd been framed so no amount of forensic evidence would ever clear him in their eyes. Ultimately, they decide to have faith in his innocence based on their personal experiences with him and not solid evidence of it.
  • Supergirl: One early comic featured a woman impersonating a man claiming to be Supergirl's husband-that-she-forgot-she-had, in order to make her (the woman's) boyfriend give up his crush on Supergirl. Supergirl saw through this at the beginning, because the woman put "his" arms around Supergirl's neck when "he" kissed her rather than around her waist, which is apparently something only girls do.
  • Superman: In Superman 1939 #76, wherein Superman and Batman learned each other's secret identities, Batman concludes that someone was lying about being an electrical engineer because he wasn't wearing rubber-soled shoes. (which has an element of Conviction by Counterfactual Clue as well: an electrician is someone who works hands-on in electrical systems installation, maintenance, troubleshooting, and repair, while an electrical engineer is usually someone who designs such systems but does not physically work on them.) On a holiday cruise. While a) Superman had X-ray-spotted a gun in the suspect's pocket and b) the guy did claim to have a job to do in a few minutes on the ship's generators, it's still rather jarring that Batman apparently concluded that no-one can own more than one set of shoes.
  • Regularly parodied in Viz magazine's strip Spot the Clue, supposedly written by a different guest celebrity every month.
    • When Tim Westwood "wrote" the strip, the murderer gave himself away by referring to an album that hadn't been released at the time the strip was set.
    • When David Bellamy "wrote" the strip, the murderer revealed himself by giving a plant's botanical name in capital letters in his speech bubble.
    • When Hugh Scully "wrote" the strip, the thief claimed she had been cleaning an Edwardian bureau at the time of the theft when the style of carving on the bureau clearly showed it being from another period.
    • When Albert Camus "wrote" the strip, the murderer's lie was to say he enjoyed life, when in fact the inevitability of death renders everything we do meaningless and absurd.
    • When Alan Sugar "wrote" the strip, the murderer claimed to have sent a message on an Amstrad eMailer, forgetting that Amstrad eMailers are shit and never do what you want them to do.
  • Trixie Belden had several comic book stories. One involved a female suspect hiding out as a guy. The crook forgot that female shirts tend to button on the opposite side. Because a woman just can't prefer to wear men's shirts, even back in the 1940s when the print series began.

    Comic Strips 
  • Subverted on Calvin and Hobbes when Susie is hit with a flurry of snowballs. She goes after Calvin, who has a wheelbarrow with him, and who protests that Susie only has "circumstantial evidence." She clobbers him anyway, and while lying face down in the snow Calvin claims that "you can't get a fair trial in this town."
  • The Swedish edition of The Phantom had a few pages of reader-submitted letters and material for a long time; one mainstay was various whodunnits, of course concocted by one of the readers. One whodunnit was a murder taking place in Germany, and one suspect claimed to have been in the woods picking berries at the time, while the other said he had been at the movies seeing a Bond movie, and remarked on Bond's funny German accent. While the readers were supposed to suspect the latter (Bond is German?), certain little-known cultural traits were at work—movies are always dubbed over with German speech in Germany, whereas picking berries in wooded areas you don't own counts as theft and/or trespassing, in contrast to Swedish law which allows it.

    Film — Animated 
  • The Lion King (2019): When Scar corners Simba on Pride Rock and prepares to kill him off, Scar gloats that Simba's expression of fear and terror is just like Mufasa just before he lost his life. However, when Simba manages to fight back and calls him out as a murderer, Scar tries to rally the lionesses by telling them not to believe Simba's claim. Sarabi immediately calls Scar out, reminding him that it was him (Scar) who claimed he didn't get to the gorge in time to save Mufasa, and asks him point blank: "Then how did you see the look in Mufasa's eyes?" Scar, after doing an Oh, Crap!, realizes he's been exposed and the final battle begins.

    Film — Live-Action 
  • In two of the three endings to Clue, Wadsworth deduces that the cook used to work for Mrs. Peacock and that Mrs. Peacock had killed her because Mrs. Peacock said that what the cook had made for dinner was one of her favorite recipes -– "and monkey's brains, though popular in Cantonese cuisine, are not often to be found in Washington, D.C."
  • Denial: Irving tries to disprove the Holocaust in this exact way, as Anthony notes: he looks for some tiny inconsistency in the testimonies, then makes the whole case seem to stand or fall on itnote . For instance, historian Robert Jan van Pelt (Mark Gatiss) shows blueprints of the Auschwitz gas chambers as described by the man who designed them, including holes in the roof used to drop in cyanide gas. Irving points out that no holes were found in the ruins of the chamber roof, and loudly declares: "No holes, no Holocaust!"note 
  • Played with in Dogma — Loki argues to Bartleby that a couple is adulterous because "No married man kisses his wife like that." Bartleby retorts that it's a good thing Loki's never had to serve on a jury. So Loki asks the couple. Hilarity Ensues.
  • Played with in A Few Good Men –- a murder victim in Guantanamo Bay's military base in Cuba had supposedly received long-awaited transfer orders for a flight early the next morning but had not packed by the time of his murder later that night nor called any friends or family back home to make preparations. When his commander is asked about this at trial, he quickly points out that there could be any number of explanations for those facts (maybe he liked to pack in the morning), and he can't be expected to explain them. However, the contradiction is enough to irritate the witness and put him on the defensive—just as planned.
  • In The Final Cut, Robin Williams' character concludes that a man he sees in a recording is someone he met years earlier when they were boys because he cleans his glasses on his shirt. Most people who wear glasses will clean them on their shirt if a more suitable cloth is not available.
  • Gattaca:
    • Towards the end Dr. Lamar says he always knew Vincent was a "borrowed ladder" (genetic inferior with the false identity of a genetic superior) because a right-handed man doesn't pee with his left hand. This may be true more often than not but it's certainly not a biological necessity.
    • Subverted regarded the murder subplot in the film. A potential suspect for the crime is dismissed because his genes bear no markers of excessive anger or proclivity to violence. This is all thrown out the window when it turns out he really did commit the murder to protect his life's ambition, rather than through anger.
  • In Harry Potter and the Prisoner of Azkaban (not in the book where it took a lot of explanations from all parties involved and pursuing every doubt before Harry believed the truth) the person who betrayed Potters was proven "guilty" because he pretended to be a rat for the last 12 years. Curiously enough, the book offers a plausible explanation why he would do this if he's innocent:he claimed he was scared for his life since a person thought to be a Death Eater tried to kill him, and others might try this as well. While this was why he was considered a suspect in the first place, it was other evidence that convinced Harry of his guilt.
  • In Inglourious Basterds, Archie Hicox, an Englishman pretending to be a German, is doing a good job of staying undercover amongst Germans... until, rather suddenly, the Gestapo officer he's been talking with says that he's given himself away. That's because Hicox, when ordering a round of drinks, uses the British hand gesture for "three" (index, middle, and ring fingers raised) instead of the German one (thumb, index, and middle fingers raised). German audiences naturally pick up on it more easily (and it's explained later for other audiences), aided as well by the fact that Hellstrom visibly reacts to it. It helps that Hellstrom was already suspicious of Hicox, such as his difficulty at a German accent,note  his hostility to Hellstrom's presence and insisting he leave, and that the Basterds have pulled the Dressing as the Enemy stunt enough times already to make any German leap at even the least suspicious of behavior.
  • Legally Blonde has one of these used by protagonist law student Elle Woods to prove her client's innocence in a murder case, and it also leads to a panicked confession by the real culprit. When Chutney, the adult daughter of the murder victim, states she was in the shower at the time of the murder happening in the same house so didn't hear gunshots, but also claims earlier the same morning she got one of her regular perms. Elle points out that as someone who had been getting said hair treatment for half her life, Chutney should know not to wet her hair so was unlikely to be in the shower. Chutney then breaks down and confesses she actually accidentally killed her own father, she'd actually been trying to murder the accused — her stepmother.
  • Not Okay: Danni's story is found out as a lie by the fact that the weather she reports in Paris at the time was different, the Notre Dame wasn't open so she can't have toured it, and the writer's group she had supposedly attended doesn't exist.


By Author:

  • Agatha Christie:
    • In one of the original Miss Marple stories in The Thirteen Problems, Miss Marple bases her conclusion on the fact that the gardener wasn't really a gardener, because he was working on Whit Monday.
    • In After the Funeral, Poirot deduces that the "murder victim" who showed up at the titular funeral was actually the murderer disguised as her. The two clues he notices? One: when the murderer later comes to the house where the repast was held supposedly for the first time, she comments on a vase of flowers that she could have only seen if she'd been there before. Two: the murder victim had a habit of twisting her head to one side when she asked probing questions, but the imposter had practiced her mimicry in a mirror and thus turned her head in the opposite direction. That's enough to start him on a path toward the real motive behind the murder.
    • In Sad Cypress, the murderer tells a particularly silly lie — namely, that she pricked her wrist on a rose in the garden; when Poirot investigates, he finds that that particular genus of rose doesn't have thorns. It's even discussed in-universe: Poirot remarks that he wouldn't have even considered that person a suspect had they not told such a stupid, pointless lie in the first place. It turns out the pinprick mark actually came from the murderer injecting herself with an emetic after poisoning a teapot and drinking from it with the victim, thus preventing herself from dying as well.
  • Isaac Asimov:
    • Lampshaded this in one of his stories, in which a character points out that in most detective stories all the detective's deductions could easily be picked apart by a competent defense lawyer and it's a good thing the detective is always able to use their deductions to make the perpetrator panic and incriminate themselves before they go to trial. That didn't stop him from flirting with the trope himself, though.
    • In one short story, two similar-looking girls work in a library. One of them murders the other, but claims she has an alibi—she was accepting a book return from a student at a certain point before the murder. The detective deduces that it was the other librarian who had accepted the book because the student shared a name with the author of THE chemical reference, period. A professional chemistry librarian could no more forget the name "Beilstein" any more than a conductor could forget an applicant named "Ludwig van Beethoven". The student recalled that the librarian had smiled at hearing his name, but the surviving librarian didn't recall anything unusual about the student. Not much evidence, but since she confesses later, that's what would matter in court.
    • Black Widowers:
      • "Spell It!": The man makes a huge deal about his name being famous after a bookstore clerk innocently asks him to spell it. Of course, this version discounts the fact that two different people may spell similar-sounding names differently, thus leading a clerk to always double-check.
      • "What Time Is It": One of those stories inverted this trope by having the shaky evidence (that an accountant would associate the phrase "half past eight" with 8:50 since "eight and a half dollars" is $8.50 and accountants are marinated in money) given to a defense lawyer with an innocent client, so that he can use it to impeach an otherwise unshakable witness. The story was written at a time when digital clocks were still relatively new. The characters admit that, while not conclusive evidence, this could be used by the guest, a defense attorney, to sow reasonable doubt in the minds of the jurors, allowing his client to be acquitted.
    • "No Refuge Could Save": Challenges like "sing the National Anthem" or "who was last year's World Champion?" were often used to find spies, at least in the movies. Dr Asimov inverts the typical approach by identifying someone as a German spy because no American could possibly know all four verses of the Star Spangled Banner. They must've been a spy who overprepared for the former challenge. Dr Asimov had very strong feelings about the song, and considered it a tragedy that Americans didn't know it. He also wrote an essay about the importance of all four verses.
    • In one of Dr Asimov's short mystery stories, the culprit is a Québécois person using a false identity of an American. The detective tricks him into revealing his true identity by asking him to write the word "Montréal", and he writes it with an accent aigu on the e, whereas someone who only spoke English wouldn't spell it that way. To rule out innocent explanations for this information, the interrogator establishes by prior questioning that the American identity doesn't speak a word of French. Never mind that you can know about the etymology of words without also knowing the language the word was originally from, or that he might have seen someone else write it "Montréal" and followed suit, or that "Montréal" is in fact the official spelling, not only in French but also in English.
    • "The Singing Bell": Since the detective is only looking for enough evidence to convince a judge to mind probe the individual, that provides justification for the shaky evidence. The mind probe can, by law, only be done to a particular individual one time in their life, so it's only performed for very serious crimes (like murder) when there's very good reason to suspect the accused is guilty, but not enough evidence to actually convict them. It's used to collect more evidence directly from the mind of the accused.
    • "The Dying Night": Wendall Urth, Phone-In Detective, deduces the killer's identity through the circumstantial evidence of "he was the one most surprised by sunlight". The flaw in this reasoning is that both Mercury and The Moon have very long nights. The assumption that the light-sensitive recording would be safe in starlight (and safely retrieved days later) could have been made by either of Dr Kaunas or Dr Talliaferro. The justification for proving which one of them killed Romero Villiers is now Conviction by Counterfactual Clue due to an astronomical assumption being proved wrong (we now know that Mercury rotates around the sun twice for every three "days").
    • Lucky Starr and the Moons of Jupiter: Bigman suspects blind Mr. Norrich of being a spy and not blind at all. His arguments are that the man is sitting with the lights on, and that he noticed when Bigman turned the lights off. However, the man provides perfectly good explanations; he realized Bigman turned off the lights because he heard him tiptoeing toward the wall and his guide dog going to sleep, and as for the lights... well, it doesn't matter to him, but it would probably matter to any friend who might come to visit.
  • John Dickson Carr specifically warns aspiring mystery writers about this kind of clue in his essay "The Greatest Game in the World." Of course, if you do what he advocates, having guilt depend on a series of clues rather than just one, you won't have that problem.
  • Woody Allen, in one of his books, wrote a parody of the detective-catching-one-mistake trope (Match Wits with Inspector Ford). The situations and answers were all absurd. For instance, a kidnapping victim returns home by asking his kidnappers if he could go to a football game that he only had one ticket for. The detective figures out that he's in on it with the kidnappers, because his parents are in their 80s and he's 60 years old, and "nobody would kidnap a 60-year-old man, as it makes no sense."

By Title:

  • One short story in the anthology Alfred Hitchcock's Sinister Spies is called "QL696.C9", by Anthony Boucher. It's about a librarian who was killed, leaving the titular mysterious sequence of letters and numbers nearby. At the end of the story, the detective gathers the suspects in the, um, library in the traditional fashion, declares that the code was probably a library subject reference number, and starts to look it up. He's interrupted by the need to keep the murderer (a spy), from killing herself with the pistol she hid in her blouse. Turns out he knew it was her as soon as he figured out what the code was for, as the killer had the only name that was a noun, and the whole library scene was just to flush her out. Fridge Brilliance kicks in when you realize that the detective needed something from the suspect to avert this trope since there's all sorts of perfectly good reasons a librarian would have to write down a Library of Congress reference code for swifts. Ironically, the anthology in question comes up when you search the LoC for the code.
  • In one of the stories in Maurice Leblanc's Arsène Lupin book The Eight Strokes of the Clock, Lupin determines that one of the extras in a silent film is infatuated with the leading lady solely from the out-of-character lustful gazes he casts upon her in the film. (These days, we'd just call that "bad acting".)
  • Subverted in Death on the Way by Freeman Wills Crofts. The police prove that one of their suspects faked his alibi for the time of the murder, and consider that this is sufficient evidence to arrest him. It turns out he isn't the guilty party—when he realised he couldn't prove his innocence, he panicked and constructed a false alibi.
  • Discussed and then averted in the novel The Franchise Affair by Josephine Tey. The novel is about two women accused of kidnapping and enslaving a schoolgirl and the attempts of their solicitor, Robert Blair, to defend them. Midway through the novel, the women's solicitor discovers a discrepancy that can be used to cast doubt on the girl's story (she could not have seen the view out of the attic window that she describes). However, Blair realises that a clever prosecution lawyer can argue around this, and even if the women are let off on this evidence, the taint of the accusations will still hang over them.
  • The short story collection Inspector Forsooth's Whodunits sets out to very deliberately avert this trope, even citing the classic example of "the English professor who 'committed suicide' and left a note filled with grammatical mistakes."
  • A Series of Unfortunate Events: Grammar Nazi Aunt Josephine's alleged suicide note contains several grammatical errors, leading the Baudelaire siblings to believe it is a forgery. It turns out that the note was genuine, but the suicide was fake, and the errors were a coded message to that effect.
  • In Terra Ignota, Papadelias, the cop who brought Mycroft in after Mycroft's two-week-long murder rampage, has known for years that there is something off about Mycroft's case, based mostly on how Mycroft seemed to be in two places at the same time while committing his crimes. Every time they run into each other, he quizzes Mycroft on the timeline, trying to find discrepancies. Mycroft always has a correct and plausible answer. Papadelias is right, though. Mycroft is hiding his lover and partner in crime Saladin, who committed half the murders.
  • Some examples from Encyclopedia Brown author Donald J. Sobol's less famous solve-it-yourself series for adults, Two-Minute Mysteries, starring Dr. (no first name given) Haledjian:
    • Haledjian knows that Nick the Nose, the informant, is lying (as he always is) because he claims that a dying Brazilian's last words were in Spanish, and the national language of Brazil is actually Portuguese. (Because the Brazilian couldn't be one of the many immigrants to Brazil from nearby Spanish-speaking countries. And because it would be impossible for a native Brazilian to speak his last words in a foreign language. And because it would be impossible for an Anglophone informant to simply mistake Portuguese for the extremely-similar-sounding and more commonly heard Spanish language.) In fact, depending on what he said, it could sound exactly the same in Spanish or Portuguese, especially from the mouth of a dying man (who presumably isn't speaking particularly clearly).
    • One of the cases involved the apparent suicide of an actor and Haledjian claiming that the note left behind was a fraud written by an English rival of the deceased because the note used "theatre" instead of "theater" and other British spellings. (Because apparently, Americans are only supposed to use American spellings. And no one ever uses "-re" to refer to stage productions and "-er" to refer to a local multiplex.) This one is particularly egregious: most actors, even American ones, probably would spell it "theatre", unless they were specifically referring to a movie house. In fact, This Very Wiki uses "Theatre" as the namespace for plays, not "Theater".
    • Another case has Haledjian declaring someone's alibi faulty because the person identified the tune a band was playing as "God Save the Queen" rather than "My Country, 'Tis of Thee" (which has the exact same tune), and so knew about a British performing troupe being in town. Many American Gilbert and Sullivan companies play "God Save the Queen" before performances, and as a Standard Snippet, it's always "God Save the Queen"; he could also simply be an Anglophile. Even worse, the actual name of the tune is "National Anthem."
    • The alleged murderer claims to have not visited his friend for days but is caught because he leapt over the freshly-painted stairs and knocked on the window set into the door rather than the freshly-painted door itself. (Because it's not like fresh paint looks and smells like fresh paint, especially fresh white paint. And because it's not like some people leap over stairs as a matter of course, or like knocking on a window is often simply louder than knocking on a heavy door.) This is one of the many cases that were recycled for Encyclopedia Brown to solve.
    • An English professor's suicide note is considered fraudulent and a product of foul play because it contains a split infinitive. (Because English professors always follow grammatical rules, even when distraught and suicidal, and all English professors accept "don't split infinitives in English" as a rule.)
    • Haledjian also dealt with the rather more plausible inversion, where the suicide note was in perfect grammatical English despite the dead man being an uneducated Italian immigrant who read the news in an Italian-language newspaper.
    • The suspect claims it is his first time in the victim's house, but when a doorbell rings, he knows to answer the back door. Because nobody can hear where a given sound is coming from, depending on how the house is built. And because there's no way at all the suspect could be from, live in, or have lived in a town where it's customary to do everything at the back door except on special occasions. And there's no way the person had a common model of doorbell that always put a specific tone/ding-dong pattern at the front, and another at the back.
    • The painting's owner claimed to be getting dressed to investigate the disturbance, with his right leg in his pants and his left leg out. (Everybody always gets dressed and undressed left-leg-first. Didn't you know that?)
    • A criminal's itinerary read "Palestine" instead of "Israel", thus revealing he wasn't actually going to the Middle East as his girlfriend claimed. (Not a lot of tolerance for potential political differences.)
    • "An arrow flight away"/"A narrow flight away": The detective was specifically looking at the flight of stairs when he said it and the suspect still replied "then why don't you go outside and look for it?", rather than "upstairs", revealing that he knew that the stolen diamond had been shot out of the house with a bow and arrow.
    • "Flawless"/"floorless" The police have confiscated a car whose floorboard was used to smuggle drugs. Haledjian is trying to catch the crooks by posing as car salesman "Flawless Phil". He mentions to one prospective buyer that "the interior is floorless"; when the buyer walks away, Haledjian orders him arrested on the grounds that had he been innocent, he would have heard "floorless" as "flawless", the slogan of the lot. While there are accents that make 'flawless' and 'floorless' sound similar or even the same, there are many more where they are quite distinct. And in either case, isn't it possible that the guy just didn't like the car or perhaps he had to take a dump? (In this case, the guy didn't help his case by acting really nervous.)
    • In one of the Two-Minute Mysteries, the suspect was caught after Haledjian said the (diamond?) was hidden in the cupola because the murderer was the only one who ran up towards the attic instead of to the kitchen. Because only a murderer could know that a cupola (usually "KOOP-ul'uh", but the pronunciation varies by person enough that "kupp-ola" wouldn't be suspicious) was a term for the little domed thing on top of the house and not just an annoying term for a cappuccino maker, that only someone who had killed the house's occupant would assume that the stairs going up lead to the roof level, and that it's impossible to see a cupola from outside the house.
    • In one case, the question of whether or not a ring bearing a very valuable jewel was stolen or legally bequeathed comes down to the accusing party's testimony. She says that when she saw the deceased for the last time (when he supposedly bequeathed it to her), he was reading a book and wearing the ring on his right hand, so when he turned a page the gem flashed brilliantly. Haledjian figures that the 'witness' is lying because the dead man was reading a book written in Hebrew before he died—and Hebrew is written right to left. The man would have been turning the left page with his left hand, not the right page with his right hand... But most people turn the page with their dominant hand, regardless of direction. If Haledjian had been correct here, then people would use a different hand to flip back through a book than to flip forward through it. Even animators knew this wasn't true. Also, Haledjian would be discounting the possibility that he was flipping back a few pages, perhaps to find a passage.
    • Sometimes, Haledjian completely disregards sheer stupidity as an answer. In one mystery, he was on his way to a BBQ when the host was found murdered. His neighbor came over, saying he heard his wife scream in horror, and during the interrogation, spotted the wife's pearl earring in the grill and reached his hand in to retrieve it. The detective told him that he obviously planted the earring because, despite having just arrived, he knew that the coals were cool enough to plunge his hand into them. Apart from the fact that coal visibly whitens when heated and that people can sense heat when standing next to hot coals, does he ever consider the fact that the guy could have just been an idiot?
    • In one case, the head of an orchestra had two skilled violinists and had to decide which would play a solo on opening night. He picks A about five minutes before the performance is meant to start. When he goes to get A, he finds A has been killed, and then has to pick B. Haledjian decides that it must have been B who did it, because B walked onto the stage, sat down, and began to play without stopping to tune his violin and rosin his bow. However, a professional performer who might have to go onstage at a few minutes' notice would be prepared in advance, not risk the wrath of the stage manager by making everyone else wait for them.
    • In one, Inspector Winters asks for bicarbonate of soda for an upset stomach while in a bakery. The baker says she doesn't have any; this leads the detective to deduce that the bakery must be a front for smuggling since bicarbonate of soda is baking soda and no real bakery would be without it. Except there's the possibility that the baker was unfamiliar with an antiquated term for baking soda (even more egregious today than when it was originally written: many modern chemists might find the term unfamiliar, since the proper scientific terminology has been "sodium hydrogen carbonate" for decades, and was "sodium bicarbonate" rather than "bicarbonate of soda" for some time before that). And then there's the possibility they ran out of baking soda using it to, you know, bake; or that they bake pies and pastries which don't require it. Pie crust isn't usually leavened at all; if it is, it usually uses baking powder — and if you do need baking soda (to raise the pH of acidic ingredients such as lemons and limes), you can easily substitute it with baking powder if you just use more. Finally, how does he know it's a front for smuggling? A lot of "fronts" are actually run fairly competently.
    • One mystery centered around a cab driver who had been badly beaten and carjacked by a woman he picked up for a fare. The detective deduced that the suspect must have actually been a man dressed as a woman, based on the fact that they had stood outside the cab while giving the address rather than waiting to sit down in the backseat. There are a dozen reasons someone—man or woman—might be more comfortable asking a driver to take them to a destination before hopping into the car, like making sure the driver is still on-duty or inquiring after fares for an odd distance.
    • Still another case hinged on the detective's belief that a real resident of San Francisco would never ever refer to the city as "Frisco." While it's true that residents of the city traditionally hate that nickname, it's not exactly an enforced law, at least not since Emperor Norton died.
    • The suspect claims to be a stranger in the house but knows that the brandy is kept in the kitchen, never mind that that's where most people keep their liquor.
    • Overlapping with Conviction by Counterfactual Clue, a person who apparently committed suicide should have had the possibility of foul play. The reason was that he recently had a heart attack, yet had salt on the table (which he should have been avoiding) and this "proved" somebody else was in the house. Because apparently, a suicidal person would adhere to health warnings, and not just that they couldn't have had a salt shaker on the table but simply not used it personally and/or kept it there for guests. This does very little to prove that someone was actually in the house.
    • In one mystery, the decisive clue to determine that the woman who owned a priceless statue had deliberately broken it for the insurance money and was lying about it being broken by accident is that in her story, she received her first mink coat but immediately put it in her closet because it was hot outside. As the book claims, "no woman would ever put away her first mink coat — she would immediately put it on and purr over it". So in the end, a horrendously sexist assumption is treated as hard evidence.
  • There was one book of "Solve it yourself mysteries" intended for kids which seemed to do something with the trope while inverting it with more common examples:
    • One case hinged on "I was woken up by thunder and then saw a man stabbed during the lightning" because lightning always comes before thunder. Yeah, makes sense, but apparently, there was only one stroke of lightning.
    • Another case from the book had a murder take place at a country club wherein someone was pushed down a hill and broke his neck in the fall. The tennis player who reported it was apparently the murderer because he had a (presumably fresh) grass stain on his shoes and of course, tennis players would have different shoes for tennis than walking around in the grass. Yes, this is indeed correct - as Tennis players keep different pairs of shoes for tennis. Except apparently, the grass stains certainly couldn't have come when he ran over to see if the victim was okay or not. (In real life, it'd have been more suspicious if he stopped to change his shoes like the detective thought he would.) This also isn't an enforced rule either.
    • Another one had a victim killed by having a heavy clock dropped on his head, and there were two murderers. All three suspects claim it was most likely an accident. Person #1's alibi was that he was watching a TV show with the deceased, and left after it ended but the clock fell down. Person #2 hears something fall to the floor from down the hall and runs to investigate, and person #3 was out smoking, then walked in and simply found #1 and #2 standing over the body. The detective says that Person #1 and #2 are guilty for several reasons. One, the clock stopped at 8:51 and no TV show ends at 8:51. This is an analog clock (the stories were written in the '70s) and evidently, there's not the possibility that it might have been simply running slowly or that the clock's hands got jarred by the impact. The second one also apparently couldn't have heard the body from the other side of the hall, but it's actually not impossible to hear something heavy fall to the floor, especially if it's a clock heavy enough to kill someone.
    • Zig-zagged with one case: A woman is assaulted at the beach. There are three suspects: a snorkeler, a skin diver, and a dog-walker. Two of them attacked the woman, the last one called the police on the payphone (It was the 1970s). The "answer" is that the dog-walker was the one who called the police — since he is more likely to have pocket change, as the others are in swimsuits. While that makes sense, apparently the caller did not think to describe what the aggressors look like, there were presumably only four people at the beach that day, and the perps didn't flee the scene of the crime. But, it's still possible (just not very likely) that either of the swimmers may have had some pocket change, such as keeping it in their shoes on the beach, and they never mentioned this.
    • Lampshaded in one story where the detective is listening to someone's testimony on a crime and mentions it won't stand up in court because he was telling the story as he saw it, through the mirror of a car. But apparently, he can't just mention "I saw it in a mirror".
  • Uncle John's Bathroom Reader had a series of simple mysteries featuring Leslie Boies and her companion, Steve. In one story, Steve tells Leslie about a man whose life was saved because the night watchman at the factory he owned told him he dreamt the train he usually took was going to crash. So the man waited for a later train, and sure enough, his usual train crashed. Leslie comments that the watchman should be fired because if he dreamt about the train, he must have been sleeping on the job. Because he couldn't have had the dream when he was back at home, clearly. This is a variant on the tale that actually introduces the element that makes this qualify; in other versions, the dreamer specifically states that he had the dream at a time when he was at work.
  • You Be the Jury: One case involved a radio DJ being kidnapped as revenge for publicizing the bad service of a local roofer. It turns out that the DJ faked the kidnapping as a publicity stunt as one piece of evidence was a photo of him after getting away from his kidnappers three days later. He was clean-shaven and the solution argues that he should have had a three-day beard.
  • A series of short plays for kids published in the UK featured a detective with the catchphrase "And I can prove it because you made four silly mistakes". The mistakes rarely proved anything. (In fact, one of them was the fallacy namer for No True Scotsman; a character during the Jacobite Rebellion is exposed as an English spy because, amongst other things, he puts sugar on his porridge...)

    Live-Action TV 
  • 24: in the first season, Jack is interrogating a businessman in his limo, trying to prove he isn't who he says he is while connecting him with the conspirators in the day's events. His initial "contradictions" are fairly shaky, such as why is an honest businessman is meeting someone in a garage unless the person was a criminal. The real clincher that he's a phony is when he tries to attack Jack with a knife he keeps in a secret compartment of the limo; why would an ordinary businessman who can presumably afford security carry a blade in his car unless the guy he was meeting with was a criminal? Perhaps the guy's just Crazy-Prepared? In this case, it may have been as much about the knife itself as the fact that it was a specialized blade: a Microtech HALO that's something only a knife nut would procure.
  • Accused (2023): In "Morgan's Story" Flaco's testimony is exposed as lies by the fact he couldn't even name what color of car Morgan drives, despite supposedly buying drugs from her every week for a long time. It proves he's committed perjury, since they neglected that small detail.
  • Blackadder Goes Forth: Played for laughs in an episode. Blackadder reveals he discovered Nurse Fletcher Brown was a German spy when he asked her if her well-educated boyfriend had been to "one of the great universities: Oxford, Cambridge, or Hull. You failed to spot that only two of those are great Universities." To which General Melchett, a Cambridge man, replies, "That's right! Oxford's a complete dump!"
  • Blue Peter annuals used to feature a regular story in which a detective called McCann and his nephew Bob would catch a thief after the thief made six (always six) factual errors. This was a fairly good example of the trope because the mistakes were things the suspect would have known if they were who they claimed to be and merely exposed them as suspicious imposters. The actual proof was that they had the stolen artifact on them.
  • Columbo: Shows up in the first regular episode "Murder By the Book", where Ken Franklin, half of a mystery writing team, sneers that Columbo doesn't have anything concrete linking him to the murder if his partner Jim Ferris—just a motive, the fact that he took out a life insurance policy on the victim, the fact that someone else was murdered shortly afterward who he claimed not to know but in whose house was found a book with a personal autograph in it, and such odd behavior as opening his mail shortly after finding the body on his lawn, and withdrawing a large sum of money out of his bank account and re-depositing it the next day. And Franklin's right, these things are all circumstantial evidence. Then Columbo points out that he found a vague story outline in the victim's office; apparently Columbo's (accurate) reconstruction of the murder matches one of the thousands of rough story ideas that Ferris had been scribbling down over the past couple of decades.note  Franklin immediately gives in, despite this being easily the weakest piece of evidence presented thus far.
  • Cracker:
    • In one episode, Fitz deduces that someone is the murderer, as they claimed to be a student and "you don't dress like a student" (because obviously, all students dress exactly the same way).
    • In another episode, he not only deduces that someone is a closet gay, but also his alibis, because when questioned he said "I was at home with my girlfriend" rather than "I was at home with Lesley"—thus showing he was afraid of saying that his girlfriend's name was a potential man's name and letting Fitz think he was at home with a man (because, of course, everybody normally says "I was at home with [name]" to complete strangers, despite the stranger not having a clue who [name] would be).
  • Criminal Minds:
    • Occasionally played with in the show, such as in "Doubt". The guy they arrest is obviously the killer, but he doesn't confess and they have no real evidence against him besides the profile, so they're forced to let him go (the fact that a Copycat Killer attacks while he's in custody helped).
    • One episode involved a serial rapist UnSub who played a particular genre of music during his crimes. The team ended up dismissing one suspect on the grounds that he had been too young to be influenced by that music when it was popular. Apparently it's an iron-clad law that your favorite music must be the music that was popular while you were a teenager, and that no one ever prefers music from a previous era. The episode's main sub-plot (a woman goes full-blown vigilante and kidnaps and tortures a suspect because she believes he's the rapist) revolves around her (apparently paranoid) belief that because she heard him play "Total Eclipse of the Heart" on the piano he's the guy — as the tortured man points out, the fact he knows how to play "Total Eclipse of the Heart" (a piano melody that is very simple to learn, and which he insists he learned for his wife, and he even plays a couple of songs that sound similar) is not conclusive evidence at all. It was him.
    • More like "Identification by Contradiction," but one episode ended with the team needing to figure out which of a pair of identical twins had killed the other. The surviving twin's claim to be Jesse is "proven" false when the boys' father, who hasn't seen them since they were toddlers and has mental problems, recognizes a nervous tic of Wallace's. This identification is enough for Wallace to drop the act and beg his mother for help. Not that the impersonation could have lasted for long, mind you, since the men both had fingerprints on file and had been Separated at Birth and lived very different lives, not to mention Wallace being the only one to inherit a degree of their father's condition... which only makes it stranger that this is what the team considers incontrovertible proof (Hotch even claims that the fingerprints can be faked, but apparently slightly twitching one's finger can't).
  • Crownies features this when a teacher accused of having sex with a student claims that a note the student had in her possession was written to his wife years earlier. Conveniently, the note happens to mention a brand of alcopop that didn't exist at the time.
  • Crownies's spinoff, Janet King, has an inversion when Alex Moreno is on trial for sending a teenage girl he'd met online (actually an undercover cop) a text message asking her to perform a sex act. Moreno's defence is that he knew he was talking to an adult from the beginning. His reasoning? No real teenager talks about their parents in a chatroom without using some kind of chatspeak term. The judge accepts this and acquits him. And then turns out to be a pedophile himself, with a long history of corruption.
  • CSI:
    • Brass once grew suspicious of a grieving husband saying "I loved my wife" as she was carried out by EMTs after a supposed bathing accident, but at the time since it was just a passing hunch, he doesn't seriously investigate the matter until it comes up again later. He still has to get the lab to find more definitive proof of foul play before he could do anything substantial and the criminal wasn't arrested by the end of the episode (though the raised suspicions were enough for the wife's life insurance company to repossess the husband's newly-bought Ferrari).
    • In another episode, while searching the house where the female victim of the week lived alone, Sara dramatically announces "the toilet seat is up—a man was here!"... without even entering the bathroom to check if maybe the victim had been vomiting in the toilet (they'd just found a lot of spoiled food in the fridge, after all), or whether she'd been interrupted in the middle of cleaning the bathroom, etc.
      • The same reasoning is used in an episode of Sliders where the main characters are in a world where there are very few men, who are kept in breeding camps. They escape with a man and hide out at his wife's home. When the feds raid the place, they determine that men had to have been there because the toilet seat was up.
  • In a non-crime example, a teenage boy is accused of being gay in Glee. He is, but the evidence presented is rather flimsy. The accuser saw him briefly look at a boy who was getting a drink at a water fountain, and she heard another boy who no longer attended their school make a vague statement. In the first instance, he was checking the other boy out, but someone taking a few seconds to look at a person getting a drink often has another explanation than the looker checking said person out. In this case, anything from, 'Yeah, I was thirsty, saw that a member of the club that's been on my case for driving away one of their members was at the fountain, and decided to find a different fountain,' to, 'I have no memory of this happening, but yeah, it's possible I was near said person when they were getting a drink and glanced at them,' would have been viable defences.
  • An episode of House ("The Tyrant") has House confront Wilson's neighbor, an amputee who claims to have lost his arm in Vietnam. House deduces from various clues that the man is a veteran of the Canadian Army, and calls him out as a fraud—only to be told that although Canada didn't take part in The Vietnam War, they did send troops to Vietnam to enforce the Paris Peace Accords, which is how he lost his arm in a landmine incident. It's also a straight example as Canadian troops did fight in Vietnam: 30,000 soldiers in all.
  • Jonathan Creek: from the fact that a piece of film supposedly secretly filmed by a stalker from over a tall fence used a pan instead of moving sideways, Creek deduced that it was taken by a short man standing on a box, and as the subject's manager was a short man, therefore it must have been him.
  • Law & Order: Criminal Intent: A suspect, a substitute teacher, says he hasn't been to Egypt and learned about the new Library of Alexandria from a magazine article. When the suspect says that the library has state-of-the-art smoke detectors and Goren didn't see that detail in the magazine article, that the guy was lying becomes a major plot point. An arguably more likely explanation, that the substitute teacher was being facetious (referencing the fact that the old Library of Alexandria burned down), isn't even considered. (On the other hand, given that it's Goren, he probably picked up on other indicators that the teacher was lying as well, and this was just the easiest to explain.)
  • Law & Order:
    • "Savior": a teenager claims she tried to lift some family jewelry for her boyfriend but when the jewels were missing, he shot her and her mother in a rage. The DA points out she could have stolen the jewelry herself without inviting her boyfriend into the house and concludes instead that she was paying the boyfriend the jewelry to murder her mother and he shot her when the jewelry was missing.
    • ADA Claire Kincaid once suspected a wife of the murder the husband had just been found guilty of. Her reasoning was that in a pretrial interview, the wife tried to cover for her husband's bank account withdrawals (which the victim was blackmailing him for) with a sloppily-crafted alibi. On the witness stand during cross-examination, she stuck to the same obvious lie with no elaboration; having known ahead of time the DA would ask about the money, she had more than enough time to come up with a more plausible explanation.
    • In another episode, a husband's conviction for the murder of his wife hinged on the theory he stole a brooch from her body the police later found with his mother. The defense brings in identical brooches to challenge the DA to prove the one they have is the right one. The victim's lover identifies the brooch from an engraving she'd made on the back of it.
    • In one episode, Cerreta and Logan interview a murder victim's family, and the son tells them that his mother wouldn't have killed his father, saying that he was with her at the time of the murder. Later in the episode, Cerreta wonders why the son didn't say she didn't kill his father, if they were together. Although the variation, while still a leap on the part of the detectives, is rather significant in that if someone is physically with you at the time of a murder, you know full well they couldn't have done it and thus have little reason to prevaricate.
  • The Mentalist:
    • In one episode, Jane quickly convinces the cops that a notoriously stingy millionaire is the culprit because he offered a reward for info on his employee's killer. After 48 hours, with no actual evidence or success at interrogation, they are legally required to release him. But as the guy is leaving the building, Jane tricks him into correcting a misquoted line from Shakespeare, contradicting his earlier claim that he neither liked nor knew the material (relevant because the victim had been killed by someone she met in a chatroom on the subject). This single slip is treated as a decisive victory and the cops immediately take him back into custody as if they now have enough evidence to make an actual case against him.
    • A variation of the old "I'm innocent" vs. "You can't prove that" giveaway is used in another episode when the main character sits down three suspects and declares that he's going to have them fingerprinted to see who accessed a certain company computer. Two of the suspects become visibly upset and protest that of course their fingerprints will be on it because it's a public terminal. The third suspect says, "Go ahead. It'll just prove that I'm innocent," which of course immediately arouses suspicion because only the culprit could know that their fingerprints won't be found.
  • Monk:
    • In "Mr. Monk and the Birds and the Bees", sports agent Rob Sherman has made it look like he shot and killed a burglar who apparently broke into his house and killed his wife (the trick is that he shot the "burglar" with a semi-automatic and the wife with a revolver, then planted the revolver on the "burglar", making great use of a Deceased Fall-Guy Gambit). Monk suspects Sherman is lying because he gave the alleged invader one single shot, instead of unloading his gun on him in a fit of rage and fear like someone would do in a situation like that. Further evidence is that the "burglar" owned a .22 caliber (which he left at home), the revolver found on the body was a .38 caliber, and there is no .38 caliber ammunition in his apartment. Nevermind it's a good deal safer to steal a gun for a crime or buy it on the black market than use one you're known to legally own, and toss the stolen one afterwards.
  • In the Monty Python "Railway Sketch" the son of a murdered man presents a British Rail restaurant car ticket as proof of an alibi when he is fingered for the crime. However, it was immediately pointed out that the specified train didn't have a restaurant car, instead being standing buffet only. The suspect attempts to further clarify his alibi, but every attempt to do so is immediately picked apart by the others present as they all seem to possess omniscient knowledge of railway timetables. Stimied at every turn, the son eventually just gives up and confesses to the murder.
  • Subverted on Murdoch Mysteries when members of a caravan are accused of burglary by the sons of several upper-class families who've been robbed. Inspector Brackenreid initially arrests the accused, but he later smells a rat when he notices the holes in the boys' story. Instead of arresting them based on that, he sets up a sting that confirms the boys' own guilt.
  • The Nickelodeon series The Mystery Files of Shelby Woo:
    • Shelby once identified a kidnapping suspect by breaking his alibi; he'd claimed he was at the movies around 8 or so but his ticket stub was for a 5:15. The suspect got irritated that she was going through his things and it was pointed out the evidence was not sufficient to point to his guilt—then he's identified based on his strange habit of drumming his fingers on his briefcase, making the same drumming sound as heard over the kidnapper's ransom call.
    • Another ep had Shelby try to identify a suspect in a smuggling case by the sound of his whistling a particular tune. She told Da Chief it had to be the musician who performed a concert in town whose song the suspect was whistling; Da Chief points out that a lot of people attended that concert and would have found the song catchy. A guy whistling that same tune walks past them and Da Chief smugly points and goes "See?"
  • One case from Mathnet on Square One TV involved a number of contradictions which made detectives Kate Monday and George Frankly suspicious of a kidnapping victim's involvement in the crime. In "The Problem of the Trojan Hamburger", amateur gem cutter Hans Ballpeen is kidnapped and the Despair Diamond is stolen afterwards. Ballpeen manages to escape and explains that he was forced to cut the diamond. Monday and Frankly are more than suspicious because of not one, but a number of contradictions in his account. First, Ballpeen was kidnapped first and then the diamond was stolen—it's reasoned that there's no point in kidnapping a gem cutter unless you have one to cut in the first place. Second, Ballpeen claimed he hadn't cut a diamond in years, which made the detectives wonder why someone that rusty would be kidnapped instead of someone more skilled. Third, Ballpeen doesn't identify the diamond as the Despair Diamond. That was considered odd since it was a world-famous diamond. Fourth, he claimed that he was released somewhere in the woods, hiked to a highway, and hitchhiked home. Kate Monday pointed out his boots were pristine and George Frankly reasons that anyone getting away from kidnappers would find first find a phone and call the police.
  • In early episodes of Star Trek: Deep Space Nine, Dr. Bashir often mentioned the one mistake he made on his final Academy exam: He mistook a preganglionic fiber for a postganglionic nerve. This was all that kept him from graduating valedictorian. But in the episode "Distant Voices", an alien in Julian's brain points out what viewers with medical training (including writer Rob Wolfe's wife) caught right away—a preganglionic fiber and a postganglionic nerve are nothing alike. The alien accuses Julian of getting it wrong on purpose, which later proves to be true, though for a different reason.
  • Deconstructed in an episode of Star Trek: The Next Generation where hearings were being held of Starfleet officers out of fear that there was a Romulan spy on board the Enterprise. One officer questioned was revealed to have falsified some personal information claiming he had a Vulcan grandfather when the grandfather was actually Romulan. The witch-hunter who started the hearings took that alone as just-about-proof that he was the spy they were searching for, but Picard and a few other Enterprise officers recognized that while the lie is cause for disciplinary action in and of itself,note  it didn't prove that he was involved with any kind of deeper conspiracy.
  • Deconstructed in an episode of Star Trek: Voyager: a copy of the Doctor finds himself in a museum seven hundred years into the future, a museum dedicated to the "Voyager incident," which claims the ship caused an entire civilization to be conquered by another race. The Doctor tries to explain what actually happened: Voyager was just making a trade deal for fuel that was misinterpreted to be a weapons deal. The Doctor could prove it wasn't Janeway who shot the first civilization's national hero, but an ambassador from the second race. However, it was pointed out that proving who fired a single weapon in what circumstances doesn't really change the broad strokes of the history the "oppressed" civilization wants to maintain. He does succeed in revealing the deception to the general population in the end, though.
  • Deconstructed in Unbelievable. Protagonist Marie Adler is the victim of a Serial Rapist, but this, along with not acting in a way even other rape victims find usual, is what causes Marie to be disbelieved by the detectives on her case. She told her friend a minor detail differently (that was not even directly about her rape) and the detectives decide based solely on this that her entire account was made up, pressuring her into recanting (then sticking to it after Marie changes her mind). On top of all that, she's also charged with false reporting, something which is noted by her public defender to be very rare.
  • Subverted in Veronica Mars: when a student accuses a popular teacher of sexual assault, Veronica quickly finds several contradictions in her story. Turns out the student actually was telling the truth except that she had changed the identity of the victim in order to protect her.
  • The West Wing invokes the trope in a minor example in the first season; after Sam discovers (after the fact) that a girl he slept with was a prostitute, he is eventually confronted by an angry CJ, who demands to know why he didn't tell her sooner. When Sam begins to act like he didn't think there was a problem, CJ preemptively shoots him down, pointing out that he asked both Josh and Toby for advice on the matter, so there's no way he can feign ignorance.

  • La Settimana Enigmistica: Usually averted by way of careful wording in this Italian puzzle magazine. The magazine often hosts logic puzzles where a detective needs to find a hole in a suspect's story, but the final question in these is usually worded as "What in the story didn't pan out and convinced the inspector that further interrogation was needed?", rather than "What factual error proved the suspect was guilty?"

  • Parodied in John Finnemore's Souvenir Programme, in which the great detective John Finnemore deduces the maid is guilty of murder because she got a crossword clue wrong. "Impossible" is not a nine-letter word.
  • One episode of The Whistler featured a man who killed his wife and made it look like a suicide. The police investigation and interrogation, conducted in the wife's apartment, has some close calls, but it looks like he's gotten away with it. The detective rises and heads for the door, ready to close the book on the case...and the wife's alarm clock goes off. Why would someone who's planning to commit suicide set their alarm clock to wake them up? The detective comes back and says it's time to restart the interrogation from the top, as the husband breaks down.

  • A popular (well, often seen) riddle for kids goes like this: The detective is in a hotel room because the hotel's director told him that a famous thief is in the hotel. Then, someone knocks at the door of the detective's room. He opens, and there's a guy, who apologizes: "Sorry, I thought this was my room." The detective arrests him immediately, and guess what, it's really the Gentleman Thief he was looking for. Oh, the reason? Because nobody will knock on the door of his own room—so the thief must've been checking whether the room was empty and he could plunder it! (Because it couldn't be, let's say, that his wife was in the room, had been taking a shower and he wanted to warn her, in case she wasn't dressed yet, and other people were in the corridor, or that he left the keys in the room while his wife stayed so he had to knock on the doors. Guess the thief is at least guilty of not inventing a good excuse.)
  • Another riddle involves the murder of a wealthy man who is killed on a Sunday. Upon being questioned, all of the servants give various alibis: "I was polishing the silver," "I was mowing the grass," etc. The "killer" is the one who claims to have been checking the mail because mail isn't delivered on Sundays—because apparently, it's impossible to forget that and just check every day out of habit. Or to have forgotten to check on Saturday, and instead get the mail the next day. Or to receive a newspaper that is delivered on Sunday. Or to get mail delivered by others than the Postal Service (how uncommon this is may vary between countries, but that's especially erroneous in the US since the USPS will deliver letters on Sunday for an extra charge).
  • Yet another one had a woman who was attacked on the walkway leading up to her house, then the robbers tied her and her family up while robbing the place; the detective, arriving an hour later, noticed his long shadow in front of him on the same path and insisted that she was in on the robbery because she hadn't noticed her attacker's shadows behind her. Because it's not like the angle of the sun would have changed, or she really hadn't noticed because she was reading a book or looking in her purse for her keys...
  • One riddle involves having to figure out why a suspect was let go. It turns out he was deaf and thus couldn't understand his Miranda rights when read to him. Aside from the fact that many deaf individuals know how to lip read,note  the whole idea hinges on Hollywood law, as no mention of him confessing is made. Obviously if he confessed the police would quickly have learned of his deafness and made sure his rights were understood, giving them in writing or through a sign language translator if necessary. A deaf person will most likely tell the police immediately they're deaf to facilitate this, if they didn't notice already.

  • In The Crucible by Arthur Miller, Sarah Osbourne is suspected of witchcraft because she muttered something after being refused alms when begging. She claims she was just reciting the Commandments, but she cannot recite them for the court and is thus convicted. This is in keeping with the overall point of the work, which is that the trials are inherently unfair and the 'evidence' is flimsy and being twisted by hysteria and malice.
  • In The Pajama Party Murders, Pettibone's deduction of the murderer relies on contradictions with old secondhand information and things that only he has observed. Of course, they then admit to the crime and pull a gun.

    Video Games 
  • In Contradiction this, along with Pull the Thread, makes up the main interaction with the game. Notably, the player cannot use the testimonies of two separate people to contradict one, the other, or both. All lines of questioning are kept separate, and thus those questioned can only ever be called out as a liar for giving self-contradicting testimony. As such, the game does rather well at avoiding any one contradiction resolving the case, with the closest the player character gets to jumping ahead of their evidence being threatening a full-scale investigation against a properly suspicious organization. Even the final contradiction doesn't completely nail the culprit down, with the reveal and arrest coming from an almost off-hand confession. In further irony, the culprit is actually the suspect who contradicts themselves the least.
  • The DOS Edutainment Game, Eagle Eye Mysteries falls victim to this at least once. Although the guilty party usually tells a very blatant lie that makes everything they say untrustworthy, you usually find other physical evidence too. Not so in one case, where a suspected Moon rock theft hinges almost entirely on the thief calling said object a sedimentary rock, despite the player researching in-game that it is physically impossible for a Moon rock to be sedimentary. No other evidence is found to implicate the suspect. (Because if you don't know your basic geology terms, you are clearly a thief.)
  • In the 1st Degree plays with this trope. While the prosecutor is required to poke holes in Tobin's testimony in order to get first-degree murder, it could be argued that Granger achieved it because Tobin had a total meltdown right there in the courtroom and revealed too much information.
  • Kingdom of Loathing has gotten into this trope as of 2016 with players taking the role of police detectives solving the day's latest in the series of "egg murders" taking place at mansions everywhere. Being unable to search for clues or evidence (although some of the suspects are doing so), or indeed take any action other than to wander the scene and interrogate suspects, this follows naturally. However, it's an inversion: most suspects are such pathological liars that if one both fingers a culprit and also correctly tells you even one verifiable fact about the scene or others you can make an arrest. Conviction By Non-Contradiction.
  • The first Knights of the Old Republic had a sidequest on Dantooine in which you determine which of two suspects is the murderer by poking holes in their testimonies. During the first round of questions, you find out that one of the two suspects lied, but he's not the murderer and it wouldn't do him justice to accuse him just based on this evidence—the truth is more complicated and can only be found out by repeatedly questioning both suspects and the forensic droid. You can also bypass the whole "logic" aspect and say that you know who did it and that your reasoning is that "fat people always lie."
  • L.A. Noire:
    • Cole accuses someone of hiding the fact that their friend was raped because when Cole asked her to describe her friend she didn't mention the fact that they were raped. This is made worse by the fact that the player needs to think to do this themselves—something which is highly non-intuitive for more reasons than just the insane nature of the accusation.note 
    • Cole asks the husband of a murder victim what size shoes he wears. The husband responds by saying, "size nines, I think". The player needs to press "lie", to prompt Cole to accuse the husband of purposefully lying to him, then present the work shoes Cole found in his bedroom, which are size eights. While not on the level of Insane Troll Logic it's still a ridiculous assumption to make for a whole multitude of reasons, particularly since it's only a single shoe size in difference (and the husband even said "I think", admitting upfront that he wasn't entirely certain).
  • Mass Effect 2 has a sidequest where Shepard must use various fragments of messages to identify which of five possibilities is the Shadow Broker's chief agent on Ilium. The solution comes down to the use of a single contradictory pronoun to give the answer -'none of the above'. Of course you are working for Liara, not the courts, and she's no longer too hung up on the whole 'reasonable doubt' thing.
  • In the DOS Game Sleuth, you play a detective investigating a murder in a mansion. There are six suspects each time you play. The ultimate breakdown of their alibis are that two pairs of them will have alibis that substantiate one another, one will claim to be alone, and the last one will have a contradictory alibi. The one with the contradictory alibi is, of course, the murderer.

    Visual Novels 
  • Averted in Episode 3 of Apollo Justice: Ace Attorney, where this is straight-up said to be an impossible act. Apollo has a very good idea of who the real killer is, but even though he's presented a pretty convincing case with quite a bit of evidence to back it up, and pointed out a load of contradictions in the witness's testimony, he's still unable to get them for the murder due to not having any evidence that actually links them directly to the crime. Apollo does eventually get them by by convincing his client to testify against the killer regarding the former's involvement in a smuggling operation led by the latter.
  • Danganronpa: Trigger Happy Havoc: The second case lampshades this tendency, with the accused killer complaining that he's being condemned over a minor inconsistency. The one doing the accusing actually admits the flimsiness of the reasoning, but their real goal is to rattle the killer badly enough that he mentions a piece of information that only the killer could know.
  • Danganronpa 2: Goodbye Despair: The first solid clue that leads to the third culprit's identity is the fact that their victim's cause of death was not by hanging, but rather by strangulation. After all, Mikan, the Ultimate Nurse, could not have missed that when her autopsies had been so accurate before, unless she was the one trying to hide it.
  • Subverted in the Safe ending of Nine Hours, Nine Persons, Nine Doors. Junpei performs an epic set-up to reveal that Ace/Hongou has prosopagnosia and can't tell the difference between faces, and thus killed "Snake" (or rather, a man dressed up as Snake to take advantage of Ace's prosopagnosia and get him to murder the guy). The accused points out that his having prosopagnosia is true, but it in no way indicates that he was a murderer, and that he just kept it a secret because he was upset by it. Junpei agrees with this and then says that the prosopagnosia reveal was just a springboard to lead to evidence that did implicate them.


    Western Animation 
  • Double Subversion in Beavis and Butt-Head, of all shows. When our heroes are accused of egging Tom Anderson's house, Butt-Head is inspired by a court reporter he saw on TV to try and discredit Anderson's testimony by pointing out that Anderson couldn't clearly identify who threw the rotten eggs at his house. The judge is about to dismiss the case when the prosecutor objects, stating that neither Anderson nor any of the police reports or court documents had ever said the eggs were rotten. He then asks how Butt-Head could have known the eggs were rotten unless he and Beavis were the ones that threw them. Butt-Head has no response, and he and Beavis are sentenced to 500 hours of community service.
  • Crashbox: The premise of Mugshots segments is this. Four people suspected of a crime state their alibis. Three of the four are found guilty, as their testimonies have a factual error, while factually sound testimony is deemed proof of innocence.
  • Zigzagged in "False Alarm", an episode of Hey Arnold!. Eugene is accused of pulling a fire alarm, and a jury of students — consisting of Arnold, Gerald, Phoebe, Helga, Harold, and Curly — is called to find him guilty. Arnold is the lone holdout (much of the episode parodies 12 Angry Men), and eventually uses this trope to prove his point: one of the pieces of evidence is a pencil from Wankyland, an amusement park, found near the broom closet where Eugene was discovered hiding. Arnold argues that Eugene couldn't own a Wankyland pencil, as he was banned from the park for somehow ruining a Thanksgiving Day parade the previous year. It's never suggested that Eugene might have had the pencil from before being banned (Arnold himself simply says that it's "not likely that he'd have one"), but it turns out to be a moot point, as the real culprit — Curly — reveals himself once Arnold makes this argument.
  • Parodied in Moral Orel, in which Orel starts a detective agency. There are two suspects when the contents of Reverend Putty's collection basket is stolen: Joe, the Devil in Plain Sight, and a clearly-innocent Marionetta. Orel ignores the expensive ice cream Joe has bought, and the fact Marionetta wasn't even in church at the time, and bases his conclusions on which Commandments they broke (or didn't break): Joe honored the Commandment about keeping the Sabbath Holy by refusing to cut his grandfather's lawn, while Marionetta broke the Commandment of honoring her parents by volunteering at a retirement center instead of going to church like she was told. If she broke one Commandment, then surely she would be the sort of person to break "Thou shalt not steal".
  • An episode of The Raccoons titled "Simon Says" involves an aardvark claiming to be Cyril Sneer's long lost brother, Simon, who wants his share of the Sneer fortune. Simon claims to have been trapped on a desert island for a long time and eventually built a boat to get himself off the island. Bert however is suspicious and spends the episode trying to expose Simon as a fraud. Bert succeeds and when asked what made him wary, it's explained that during their initial handshake, Bert noticed Simon's hands were very smooth. If he had worked on building his own boat, his hands should have been rough and callused.
  • Rugrats had an episode like this titled "The Trial." After Tommy's favorite clown lamp is broken, Angelica suggests that he hold a trial to determine the culprit. Angelica plays the role of "persecutor" and attempts to finger Phil, Lil, and Chuckie as the "poopatrator", pointing out their various actions that endangered the lamp, but they're able to defend themselves. It isn't until Tommy realizes that Angelica's supposed "alibi" — she was taking a nap — doesn't hold up because she supposedly took one earlier at her own house (the episode opens with her coming into the room after "waking up," but she's clearly lying) that the babies realize that it would have been impossible for her to know what exactly they were doing and thinking unless she was there, which she was.
  • The Simpsons:
    • In "Krusty Gets Busted", the first Sideshow Bob episode, Bart and Lisa's investigation basically comes down to this. First Lisa realises that Krusty wouldn't have used the Kwik-E-Mart microwave because he has a pacemaker, then that he couldn't have been reading the Springfield Review of Books at the magazine rack because he can't read. When Bart brings these points up on Sideshow Bob's show, Bob argued that Krusty wasn't one to follow medical warnings, and didn't need to be able to read to enjoy the Springfield Review of Books, thanks to the cartoons. Finally, in a "Eureka!" Moment, Bart remembers that Homer stepped on the ends of fake Krusty's long shoes, causing him to exclaim in pain. Although Krusty usually wears oversized shoes, his feet don't fill them, so he wouldn't have felt a thing; Sideshow Bob, however, has feet long enough to fill the shoes.
    • Parodied in a random Duff poster that appears on an episode where Homer and Barney visited the local plant, which (having been done during The Cold War) had someone accused of being a Communist spy and arrested simply because he didn't like Duff.
    • Spoofed in "Hungry, Hungry Homer" where Homer finds evidence that the Duff corporation, owners of the Springfield Isotopes, are planning on selling the team to New Mexico but nobody believes him because the owners hid said evidence. Homer goes on a hunger strike to get Henry Duff VIII to tell the truth, which he exploits as a publicity stunt. When it looks like Homer's about to give up, Duff offers him a hot dog; however, he notices the toppings (mesquite-grilled onions, jalapeño relish, mango-lime salsa) and observes "That's the kind of bold flavor they enjoy in...Albuquerque!" This is treated as the smoking gun that proves Homer right, despite the fact that there's absolutely no reason a stadium couldn't just choose to serve a Southwestern-style hot dog. Also, the hot dog wrappers say "Albuquerque Isotopes", but apparently nobody noticed that until Homer brought it up.

    Real Life 
  • One of the Al-Qaeda bombers who attacked the US Embassy in Nairobi was rumbled this way. He was supposed to have committed suicide after his task (to throw a sound grenade into the courtyard to draw people to the windows before the bomb hit) was complete, but suddenly found a very good reason not to, and fled to a hotel in the suburbs. When the Agency interviewed him, he told them that he was wearing the same clothes he had worn on the day of the explosion. But they were pristine, whilst the CIA agents' clothes were worn after only a few days in the country. Then, he claimed he washed them. Not impossible. However, his belt, which he claimed to have been wearing on the day of the blast, was pristine, as opposed to the worn straps Kenya had made of the CIA's. And you don't wash a belt, so it must have been put on later, so the man must have been lying. When this error was pointed out to him, he spilled all.
  • Shibboleth: A word or custom specific to a particular group or subculture that most outsiders incorrectly identify or pronounce. Getting the name or tense of a local slang, street or landmark can identify someone as a foreigner at best (see the myriad differences in the ways Americans vs. Canadians pronounce words like about) and a German spy at worst (see the Isaac Asimov short story with the Star Spangled Banner). Shibboleths were used in history during ethnic and cultural conflicts as tests to distinguish an outsider trying to conceal themselves and the penalty was typically execution on the spot, as in the Word Origin, the biblical story in the Book of Judges of the execution of Ephraimite refugees who mispronounced "Shibboleth" as "Sibboleth". That Other Wiki has a full breakdown of the subtle differences in American and British English that are possible Shibboleths in everyday conversation.
  • A public defender recalled a story on The Moth Radio Hour, in which he was defending a man accused of smashing a window with a paint can by throwing it in from outside. It was an incredibly minor charge, and the prosecutor was willing to drop it if the defendant would just pay for the cost of replacing the window. However, the defendant swore up and down that he hadn't smashed the window (for extra salience, there was apparently a woman involved, that both the defendant and the window's owner were having sex with), and wanted to go to trial. During pre-trial prep, the public defender noticed that the prosecutor wasn't going to call the police officer that responded to the original complaint, which struck him as odd. He, however, had spoken to the police officer, and he therefore knew that he was going to win the case. He called the officer to the stand (which is extremely rare, for a cop to be called as a witness for the defense), and asked if the owner of the window had allowed the officer into the room with the smashed window. Well, no, replied the officer. Alright, did you get to see the paint can? Well, no, replied the officer. Did you get to see the shattered window? Yes, the officer replied, but only from outside. And where was the broken glass? Well, replied the officer, it was on the outside of the window...
  • As shown on HBO's McMillions, one of the fake McDonald's Monopoly winners identified a location in Florida as the one in South Carolina (a different state) where she had purchased her ticket. But it's not obvious that one McDonald's will look a lot different from another, and it's entirely possible to confuse the two.
  • Although a civil trial and not a criminal trial, Johnny Depp’s 2020 UK defamation case against a tabloid for calling him a "wife beater" was largely lost on him and his inner circle not being able to keep their stories straight. One instance of Depp's alleged abuse of ex-wife Amber Heard was on a chartered flight in 2014 in which he kicked her in a drunken rage. His assistant, who'd seen the kick, had to admit on the stand that texts between him and Heard that he'd long tried to pass off as fake in which he apologized on Depp’s behalf for the kick and telling her Depp had cried when told once he sobered up were genuine. Depp himself also said he'd remembered the flight in his witness statement but admitted on the stand that he hadn't written it and didn't remember the flight. Another instance revolved another of Depp's employees saying an incident in 2016 was instigated by Heard by presenting pictures of Depp with a bruised face but the phone data proved they’d been taken a year earlier and only a few days after a time where Heard had admitted she'd hit him in defense of her sister whom she believed was about to be pushed down a flight of stairs. The employee couldn't explain the discrepancy and the judge therefore reduced the weight of his statements.
  • A well-known Australian judge named Marcus Einfeld was caught in a lie this way. His car had been caught by a speeding camera going ten kilometres over the limit, resulting in a 77 AUD ticket and three demerit points on his driving license. To avoid the fine and demerit points, he said, while under oath, a friend visiting from the United States had been driving at the time, and the ticket was dismissed. However, the editor for a local tabloid discovered that Einfeld's friend who had supposedly been driving the car had died three years prior. When confronted by this fact, Einfeld concocted a massively ballooning Snowball Lie to try and explain this discrepancy; first claiming it was someone else with the same name, then making up a twenty-page document detailing his extensive interactions with this made up person, and another person independently attempting to advocate for him by stating she was also with him in the car and the supposed driver. He eventually admitted it was all a lie, served two years in prison for lying under oath and perverting the course of justice, was disbarred, and his status as a National Living Treasure was revoked (one of only two times this has ever occurred). All to avoid a fine he could have easily paid.
  • Alicia Head was infamous for claiming to be a survivor of the World Trade Center terrorist attacks, and later became president of a 9/11 survivor support group, being frequently interviewed and invited for conferences about her "experience", which she recounted in great detail, including the death of her fiancé/husband "Dave" in the attack. However, her claims were disputed in a report by The New York Times which found the friends and family of "Dave" had never heard of Head, and the company she supposedly worked for at the time had no record of her employment, nor did the company even have offices in the towers; she also claimed to have degrees from both Harvard and Stanford University, but neither institution had any records of her attendance. Following this report, Head refused all further interviews, went into hiding, was stripped of the group's membership, and basically fled the country. It later came out she had not even been in the same hemisphere as the attacks; she had been attending classes in Barcelona at the time. This inspired the film Not Okay, whose protagonist claims similarly that she survived a terrorist attack and is caught out in a similar manner.
  • One viral video showed a hearing about fracking wastewater disposal dumping and potential contamination. One local challenged a committee member to drink the "safe" water like he claimed he'd do, even though it was visibly dirty. The member refused. This "proved" that he was a lying hypocrite. Except in longer videos, the local admits he mixed up random water, to make a point about how the locals are just expected to take a risk on undisclosed and potentially dangerous fracking chemicals. The actual dumping hadn't even started yet. So the local was making a decent point, but Manipulative Editing was done for a "punchier" David vs. Goliath narrative.


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Alternative Title(s): Bugs Meany Is Going To Walk, Bugs Meany Is Gonna Walk


People of Illinois v Armstrong

Before he went into politics, Abraham Lincoln was a lawyer. In one of the most famous cases he took, he defended family friend William "Duff" Armstrong against a murder charge by pointing out that the weather in head witness Charles Allen's testimony didn't match up with records. While Allen isn't the one who did it, his credibility as a witness was shattered, and the case was over.

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Main / ConvictionByContradiction

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