History Main / ConvictionByContradiction

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. However, an acquittal in such a case is not a slam dunk. The jury has the power to weigh conflicting evidence may still find the defendant guilty. Such convictions have been affirmed on appeal.

* [[http://en.wikipedia.org/wiki/Shibboleth 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 [[TropeNamers Word Origin]], the biblical story in the Book of Judges of the execution of Ephraimite refugees who mispronounced "Shibboleth" as "Sibboleth". [[Website/{{Wikipedia}} That Other Wiki]] has a full breakdown of the [[http://en.wikipedia.org/wiki/Comparison_of_American_and_British_English subtle differences in American and British English]] that are possible Shibboleths in everyday conversation.

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.

* ''Manga/CaseClosed'': 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.

** 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. Yeah, you'd have a point there, since many tennis players keep a separate pair of shoes specifically for tennis the way people do for a lot of sports. 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.)

** 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 [[TechnologyMarchesOn 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 [[FacePalm did not think to describe what the aggressors look like]], there were presumably only four people at the beach that day, and [[TooDumbToLive 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. It also ignores the fact that calls to emergency numbers such as 911 are free, so nobody would have needed any change for the phone!

* In ''Series/{{Unbelievable}}'', protagonist Marie Adler is the victim of a SerialRapist, 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.

* Averted in Episode 3 of ''VisualNovel/ApolloJusticeAceAttorney'', 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 [[spoiler:forcing a confession out of him.]]

* A well-known Australian judge named [[https://en.wikipedia.org/wiki/Marcus_Einfeld 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 SnowballLie to try and explain this discrepancy; first claiming it was someone else with the same name, made up a twenty-page document detailing his extensive interactions with this made up person, and another person independently attempted 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 court of justice, was disbarred, and his status as a National Living Treasure was revoked (one of only two times this has ever occurred).
* [[https://en.wikipedia.org/wiki/Alicia_Esteve_Head 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.

* Although a civil trial and not a criminal trial, Creator/JohnnyDepp’s 2020 UK defamation case against against a tabloid for calling him a “wife beater” was largely lost on he and his inner circle not being able to keep their stories straight. One instance of Depp’s alleged abuse of ex-wife Creator/AmberHeard 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 was believed was about to be pushed down a flight of stairs. The employee couldn’t answer the discrepancy and the judge therefore reduced the weight of his statements.

** 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, [[Website/TVTropes This Very Wiki]] uses "Theatre" as the namespace for plays, not "Theater".

* One short story in the anthology ''Creator/AlfredHitchcock's Sinister Spies'' is called "[=QL696.C9=]", by Creator/AnthonyBoucher. 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,[[spoiler: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. FridgeBrilliance 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 [[spoiler:for swifts]]. Ironically, the anthology in question comes up when you search the [=LoC=] for the code.

** 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, you can easily substitute it for 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.

* Played for laughs in an episode of ''Series/{{Blackadder}} Goes Forth'': 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!"

[[folder:Other]]
* ''Series/BluePeter'' 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.
* Usually averted by way of careful wording in the Italian puzzle magazine ''[[https://en.wikipedia.org/wiki/La_Settimana_Enigmistica La Settimana Enigmistica]]''. 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 an article from Website/TheOnion about [[https://www.theonion.com/idaville-detective-encyclopedia-brown-found-dead-in-lib-1819567098 the boy detective's murder]]. Bugs claims that "at the time the crime was committed, I was at [[PolarBearsAndPenguins the North Pole watching the penguins]]".
* The TabletopGame/PerplexCity card "Alibi" pegs [[spoiler: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.)

* ''Manga/CaseClosed'': 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 up being slowed).

* 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 be wearing the foot warmer at the time.

* ''ComicBook/{{Supergirl}}'': One early comic 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.

* 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. [[note]]Current political controversies notwithstanding, prior to the 1967 War the non-existence of Palestine was indeed generally considered a non-controversial matter.[[/note]]

-->'''Charlie:''' In conclusion, only thing evil man like Motley really need was far better alibi.

* [[PlayingWithATrope Played with]] in ''Manga/CaseClosed'' -- 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 up being slowed).
* Inverted in ''Manga/{{Itsuwaribito}}''. The protagonists find out that a miracle religion is a front for a money scam. Both the founder and the first pupil claim that they are innocent and the other was manipulating him to get money. The protagonist asks both of them privately what happened. He first asks the pupil about what the founder did with the money, and the pupil answers that the founder never let anyone else close to it. Then the protagonist asks the founder how he didn't notice the money next to boxes of equipment, and the founder answers that he didn't notice the boxes of money. The protagonist finds that the founder is innocent because the founder incorrectly stated that the money was put into boxes when it was actually placed inside bags ''next'' to boxes. If the pupil was telling the truth, then the founder would have known that the money was put inside bags.

* The Swedish edition of ''ComicStrip/ThePhantom'' 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.
* One early ''Comicbook/{{Supergirl}}'' 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.
* The first storyline in which Franchise/{{Superman}} and Franchise/{{Batman}} learned each other's secret identities (via ContrivedCoincidence) featured Batman concluding that someone was lying about being an electrical engineer because he wasn't wearing rubber-soled shoes.[[labelnote:*]]Which has an element of ConvictionByCounterfactualClue 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.[[/labelnote]] ''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 "[[InformedAbility The World's Greatest Detective]]" apparently concluded that no-one can own more than one set of shoes.

%%* Parodied in [[http://www.gocomics.com/pearlsbeforeswine/2008/01/13 this]] ''ComicStrip/PearlsBeforeSwine'' comic.

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

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 [[BigSecret Bob was lying because he was doing something embarrassing that still wasn't, you know, murder]].

* 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 [[TropeNamers fallacy namer]] for NoTrueScotsman; a character during the Jacobite Rebellion is exposed as an English spy because, amongst other things, he puts sugar on his porridge...)

** 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 [[TechnologyMarchesOn 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 [[FacePalm did not think to describe what the aggressors look like]], there were presumably only four people at the beach that day, and [[TooDumbToLive 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.

* ''Film/LegallyBlonde'' has one of these used by protagonist law student Elle Woods to prove her client's innocence in a murder case, and [[spoiler: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. [[spoiler:Chutney then breaks down and confesses she actually accidentally killed her own father, she'd actually been trying to murder the accused -- her stepmother.]]

** 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 grass stain on his shoes and of course, tennis players would have different shoes for tennis than walking around in the grass. Yeah, you'd have a point there, since many tennis players keep a separate pair of shoes specifically for tennis the way people do for a lot of sports, but 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.)
** 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 at the time of the murder. 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.

* Book 1, Chapter 9 ("The Case of the Missing Roller Skates"): Combining with "INeverSaidItWasPoison", Encyclopedia is at the dentist's and has his roller skates stolen. The perp [[INeverSaidItWasPoison 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 [[NewerThanTheyThink since around the 40s or 50s]].)

[[folder:Anime and Manga]]
* [[PlayingWithATrope Played with]] in ''Manga/CaseClosed'' - 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 up being slowed).

* In two of the [[MultipleEndings three endings]] to ''Film/{{Clue}}'', Wadsworth deduces that the cook used to work for Mrs. Peacock [[spoiler: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."

* Played with in ''{{Film/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. HilarityEnsues.
* Played with in ''Film/AFewGoodMen'' – 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—[[XanatosGambit just]] [[ZigzaggingTrope as planned.]]

* ''Film/LegallyBlonde'' has one of these used by protagonist law student Elle Woods to prove her client's innocence in a murder case, and [[spoiler: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. [[spoiler:Chutney then breaks down and confesses she actually accidentally killed her own father, she'd actually been trying to murder the accused - her stepmother.]]

** 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. Pies usually use baking ''powder'' - and if you do need baking soda, you can easily substitute it for 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.

** Overlapping with ConvictionByCounterfactualClue, 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.

** 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'' strike of lightning.

** 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 at the time of the murder. 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, skin diver, and a dog-walker. Two of them attacked the woman, the last one called the police on the payphone (It was [[TechnologyMarchesOn 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 [[FacePalm did not think to describe what the aggressors look like]], there were presumably only four people at the beach that day, and [[TooDumbToLive 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.

* In early episodes of ''Series/StarTrekDeepSpaceNine'', 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 ''Series/StarTrekTheNextGeneration'' 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]]not for the ''content'' of the lie, but just for the act of lying on his official record[[/note]] it didn't prove that he was involved with any kind of deeper conspiracy.
* Deconstructed in an episode of ''Series/StarTrekVoyager'': 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 [[PoliticallyCorrectHistory wants to maintain]]. He does succeed in revealing the deception to the general population in the end, though.

* [[PlayingWithATrope Played with]] in ''Manga/CaseClosed'' - 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 up being slowed).

* The Swedish edition of ''ComicStrip/ThePhantom'' 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.
* One early ''Comicbook/{{Supergirl}}'' 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.
* The first storyline in which Franchise/{{Superman}} and Franchise/{{Batman}} learned each other's secret identities (via ContrivedCoincidence) featured Batman concluding that someone was lying about being an electrical engineer because he wasn't wearing rubber-soled shoes.[[labelnote:*]]Which has an element of ConvictionByCounterfactualClue 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.[[/labelnote]] ''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 "[[InformedAbility The World's Greatest Detective]]" apparently concluded that no-one can own more than one set of shoes.

* The ''ComicBook/BruceWayneFugitive'' 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.

* Subverted on ''ComicStrip/CalvinAndHobbes'' 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."

* ''Film/LegallyBlonde'' has one of these used by protagonist law student Elle Woods to prove her client's innocence in a murder case, and [[spoiler: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. [[spoiler:Chutney then breaks down and confesses she actually accidentally killed her own father, she'd actually been trying to murder the accused - her stepmother.]]

* In ''Film/HarryPotterAndThePrisonerOfAzkaban'' (''not'' in [[Literature/HarryPotterAndThePrisonerOfAzkaban 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 [[spoiler: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:[[spoiler: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 ''Film/InglouriousBasterds'', 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 [[OohMeAccentsSlipping his difficulty at a German accent]],[[note]]Hicox tries to cover it by claiming to be from the Swiss-Italian border region, even though their dialect is entirely different[[/note]] his hostility to Hellstrom's presence and insisting he leave, and that the Basterds have pulled the DressingAsTheEnemy stunt enough times already to make any German [[JustifiedTrope leap at even the least suspicious of behavior]].
* In two of the [[MultipleEndings three endings]] to ''Film/{{Clue}}'', Wadsworth deduces that the cook used to work for Mrs. Peacock [[spoiler: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."
* In ''Film/TheFinalCut'', Creator/RobinWilliams' 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.

* ''Film/{{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 it[[note]]This is TruthInTelevision for a great deal of conspiracy theorists. Sometimes they point to a great deal of alleged "anomalies" in the official story that ''still'' wouldn't actually support the alternative theory.[[/note]]. For instance, historian Robert Jan van Pelt (Creator/MarkGatiss) 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]]This is because the SS dynamited it to cover up the mass murders, leaving it mostly collapsed.[[/note]]

* Creator/IsaacAsimov:
** {{Lampshade|Hanging}}d 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.
** ''Literature/BlackWidowers'':
*** "Literature/SpellIt!": 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.
*** "Literature/WhatTimeIsIt": 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.
** "Literature/NoRefugeCouldSave": 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 [[SecondVerseCurse no American could possibly know all four verses of the Star Spangled Banner]]. They must've been a spy who ''over''prepared for the former challenge. [[WriterOnBoard 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.
** "Literature/TheSingingBell": Since the detective is only looking for enough evidence to convince a judge to mind probe the individual, that provides [[JustifiedTrope 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.
** "Literature/TheDyingNight": Wendall Urth, PhoneInDetective, 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 {{UsefulNotes/Mercury}} and UsefulNotes/TheMoon 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 ConvictionByCounterfactualClue due to an [[ScienceMarchesOn astronomical assumption being proved wrong]] (we now know that Mercury rotates around the sun twice for every three "days").
** ''Literature/LuckyStarrAndTheMoonsOfJupiter'': 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.
* 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 [[TropeNamers fallacy namer]] for NoTrueScotsman; a character during the Jacobite Rebellion is exposed as an English spy because, amongst other things, he puts sugar on his porridge...)
* One short story in the anthology ''Creator/AlfredHitchcock's Sinister Spies'' is called "[=QL696.C9=]", by Creator/AnthonyBoucher. 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,[[spoiler: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. FridgeBrilliance 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 [[spoiler:for swifts]]. Ironically, the anthology in question comes up when you search the [=LoC=] for the code.
* Creator/WoodyAllen, 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."
* Creator/JohnDicksonCarr 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.

* In one of the stories in Maurice Leblanc's Literature/ArseneLupin 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".)
* Creator/AgathaChristie:
** In one of the original Literature/MissMarple stories in ''Literature/TheThirteenProblems'', Miss Marple bases her conclusion on the fact that the gardener wasn't really a gardener, because he was working on Whit Monday.
** In ''Literature/AfterTheFuneral'', Poirot deduces that [[spoiler: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, [[spoiler:but the imposter had practiced her mimicry in a mirror and thus [[ImposterForgotOneDetail turned her head in the opposite direction]]]]. That's enough to start him on a path toward the real motive behind the murder.
** In ''Literature/SadCypress,'' the murderer tells a particularly silly lie -- [[spoiler: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. [[spoiler: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.]]
* Discussed and then averted in the novel ''Literature/TheFranchiseAffair'' 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.

* Subverted in ''Death on the Way'' by Creator/FreemanWillsCrofts. 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.
* In ''Literature/TerraIgnota'', 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. [[spoiler:Papadelias is right, though. Mycroft is hiding his lover and partner in crime Saladin, who committed half the murders.]]
* The short story collection ''Inspector Forsooth's Whodunits'' sets out to very deliberately [[AvertedTrope avert this trope]], even citing the classic example of "the English professor who 'committed suicide' and left a note filled with grammatical mistakes."

* Parodied in ''Radio/JohnFinnemoresSouvenirProgramme'', 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.

* The first ''VideoGame/KnightsOfTheOldRepublic'' 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 "[[Funny/KnightsOfTheOldRepublic fat people always lie.]]"

* The DOS EdutainmentGame, ''VideoGame/EagleEyeMysteries'' 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.)
* ''VideoGame/InThe1stDegree'' 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.
* In ''VideoGame/{{Contradiction}}'' this, along with PullTheThread, 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, [[spoiler: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.]]
* ''VideoGame/KingdomOfLoathing'' 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. [[spoiler: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.]]

* Subverted in the Safe ending of ''VisualNovel/NineHoursNinePersonsNineDoors''. Junpei performs an epic set-up to reveal that [[spoiler:Ace/Hongou]] has [[spoiler:prosopagnosia and can't tell the difference between faces]], and thus killed [[spoiler:“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 [[spoiler: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 [[spoiler:prosopagnosia reveal]] was just a springboard to lead to evidence that ''did'' implicate them.

* The TabletopGame/PerplexCity card "Alibi" pegs [[spoiler: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.)
* Parodied in an article from Website/TheOnion about [[https://www.theonion.com/idaville-detective-encyclopedia-brown-found-dead-in-lib-1819567098 the boy detective's murder.]] Bugs claims that "at the time the crime was committed, I was at [[PolarBearsAndPenguins the North Pole watching the penguins]]".

* Usually averted by way of careful wording in the Italian puzzle magazine ''[[https://en.wikipedia.org/wiki/La_Settimana_Enigmistica La Settimana Enigmistica.]]'' 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?"

* Zigzagged in "False Alarm," an episode of ''WesternAnimation/HeyArnold''. [[ButtMonkey 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 ''Film/TwelveAngryMen''), 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 [[NoodleIncident 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.