History Main / ConvictionByCounterfactualClue

* In "Ego Trip", Creator/JohnByrne's story in ''[[Franchise/{{Batman}} Batman]] 3D'', a receipt is found that mentions delivery of "zzxjoanw" to the victim. The cops figure it must have been some garbled message to someone named "Joan". Batman, armed with encyclopedic knowledge, knows that a zzxjoanw is actually a Maori drum and deduces that the victim was a collector of obscure musical instruments. The problem is that in real life, "zzxjoanw" is actually a fictitious entry in a 1903 music encyclopedia that managed to make it into two other books of "interesting words" over the next 50+ years, and no such instrument actually exists (Maori doesn't even have the letters Z, X, and J).
* Happens InUniverse in a ''ComicBook/DisneyDucksComicUniverse'' story. Hewey, Dewey and Louie see a celebrity order carrots in a restaurant, and -- since said celebrity hates carrots, as stated on every magazine -- they deduce that he must be an impostor, and the original has been kidnapped. The story ends with them freeing the real celebrity, who invites them to dinner as a thank-you... and orders a dish of carrots. When Hewey, Dewey and Louie express their incredulity, he answers "Why, do you really believe everything magazines print out?"

** One ''ComicBook/SupermansPalJimmyOlsen'' comic featured Jimmy [[WholesomeCrossdresser crossdressing]] to test the detective skills of his fanclub. They found him out in part because "Jackie" had tied a bowtie into a garter, to show "herself" as a member of the club, and according to them, "girls don't wear neckties and never have the practice to tie them ''that'' well." This is probably news to the millions of women who [[CantTieHisTie help their boyfriends, sons, or husbands with getting their ties on]], not to mention the girls that have to wear ties as part of a [[CatholicSchoolGirlsRule school uniform]].

* In the 1980s and 1990s, the Swedish edition of ''ComicStrip/ThePhantom'' had a page of reader-submitted material, of which one of the more popular were crime mysteries (see ConvictionByContradiction for more details). One of these had the culprit give himself away by referring to the banana as a fruit. Even though banana trees are herbaceous plants, a banana is biologically considered a fruit. Even when using the culinary term for fruits (which is probably the term most people outside of the fields of biology, botany, and horticulture are familiar with), this still doesn't exactly excuse the conviction, as the banana is one of the most classic examples of a "Culinary Fruit." (For a more specific description, a culinary fruit is any edible fruit that is sweet. Biologically, a fruit is a plant structure that contains seeds. This is why things like tomatoes, peppers, eggplant, and cucumbers are classified as fruits by botanists, but not by chefs.)
* An issue of ''ComicBook/PowerGirl'' featured an exploration of this, when [[Franchise/{{Batman}} Bruce Wayne]] gives the corpse of a supposed suicide victim an autopsy. He points out that the bullet wound is on the forehead, at which Dick Grayson points out that it's not unheard of in suicides. He then points out that the exit wound suggests the bullet came from straight-on, and Dick again points out that it's weird, but not impossible. Then he points out that the angle suggests the gun was being held in the victim's left hand when they were right-handed, and Dick points out that the victim was a BadassNormal and reasonably able with his left hand. Bruce responds by pointing out that, yes, it's ''possible'' that the victim held the gun to his head at a bizarre angle with the wrong hand, but it's not ''likely'', and Dick keeps focusing on the least likely possibility - which is what causes them to conclude that they're being influenced mentally. And just to nail the coffin, he gives a much less disputable bit of evidence; namely, the bullet hole is [[PrettyLittleHeadshots too neat]] for a gun-to-the-head shot.
* One ''ComicBook/SupermansPalJimmyOlsen'' comic featured Jimmy [[WholesomeCrossdresser crossdressing]] to [[ItMakesJustAsMuchSenseInContext test the detective skills of his fanclub]]. They found him out in part because "Jackie" had tied a bowtie into a garter, to show "herself" as a member of the club, and according to them, "girls don't wear neckties and never have the practice to tie them ''that'' well." This is probably news to the millions of women who [[CantTieHisTie help their boyfriends, sons, or husbands with getting their ties on]], not to mention the girls that have to wear ties as part of a [[CatholicSchoolGirlsRule school uniform]].

** Book 1, chapter 5 ("The Case of the Bank Robber"): Encyclopedia Brown deduces that the blind witness is lying because he has a newspaper in his room. Ignoring all the reasons one might have a newspaper one can't read in one's room,[[note]]Perhaps the hotel hands out complimentary newspapers; maybe he was using it to wrap something, or he bought something that came wrapped in the newspaper; maybe he was going to do a messy project and needed a disposable surface[[/note]] it isn't even necessarily true that blind people can't read newspapers. Most legally "blind" people still have some amount of vision, and depending on the exact nature of the vision loss, it's entirely possible to be able to read a newspaper (perhaps with magnification).

An incredibly common example of this is the bog-standard mystery-story reveal [[ASinisterClue that a suspect is left-handed]] and simply couldn't have performed the murder in question since it was done by a right-handed person (or vice-versa.) True enough as far as it goes, but this ignores the existence of both ambidexterity (a person with the ability to use either hand interchangeably, admittedly incredibly rare) and cross-dominance (someone who uses one hand to perform some tasks but the opposite hand to perform others, such as writing with their left but throwing a ball with their right; this one not only exists genetically but also due to many left-handed people learning to use right-handed tools such as scissors out of a matter of necessity.) Exploring the possibility of this never happens; someone sees a suspect pick up a pen with the "wrong" hand and they're cleared.

An incredibly common example of this is the bog-standard mystery-story reveal that a suspect is left-handed and simply couldn't have performed the murder in question since it was done by a right-handed person (or vice-versa.) True enough as far as it goes, but this ignores the existence of both ambidexterity (a person with the ability to use either hand interchangeably, admittedly incredibly rare) and cross-dominance (someone who uses one hand to perform some tasks but the opposite hand to perform others, such as writing with their left but throwing a ball with their right; this one not only exists genetically but also due to many left-handed people learning to use right-handed tools such as scissors out of a matter of necessity.) Exploring the possibility of this never happens; someone sees a suspect pick up a pen with the "wrong" hand and they're cleared.

** One story overlaps with ConvictionByContradiction - where an inspector has an upset stomach and asks for "Bicarbonate of soda" at a bakery. When they say they don't have any, he somehow deduces they're a front since that's baking soda and no bakery would be without it. On top of all the various reasons for why the baker may not have any (they're out, he doesn't know what it means since it was called "Sodium Bicarbonate" instead), the bakery is also stated to have been one for pies - pies use baking ''powder'', not baking ''soda''. While baking soda can be used to lower the pH of acidic ingredients (such as lemons and limes), it's not often used for pies and one can easily replace it with more baking powder since Baking Powder is just baking soda with cream of tartar.

[[quoteright:350:[[ComicBook/SupermansPalJimmyOlsen https://static.tvtropes.org/pmwiki/pub/images/bowtie_3.jpg]]]]

* The ''Series/{{Monk}}'' episode "Mr. Monk Is At Your Service" has Monk and Natalie meeting with her parents when they mention that two of their friends died in a car accident and that the car was a Morgan. Monk becomes suspicious because Morgan is a British manufacturer, the British drive on the left, and their cars are right hand drive (the steering wheel is on the right) as a result which doesn't correspond to the positions of the victims' bodies. Apparently, Monk doesn't know that most British car manufacturers, including Morgan, build left hand drive cars for export to countries that drive on the right. Also, wouldn't the position of the steering wheel be noted in the accident report?

** An alleged suicide note from a linguistics professor is determined to be a fake due to some grammatical "mistakes" that a true linguist would never make, including the use of a split infinitive such as "''to'' '''''boldly''''' ''go''". First, correctness of split infinitives is a matter of great debate; while some do abhor them, many have no problem with them at all. Second, Sobol mixes up ''linguists'' with ''grammarians''; the former being a study of aspects of a language such as what sounds are meaningfully distinct, how it expresses things that will take place in the future, and other stuff like "is there a separate word for 'hand' vs 'arm' or do they use only one word?" while the latter being the study of restraints on words and the order they go in. Finally, that's before you have to wonder if a person ''contemplating suicide'' is in the correct frame of mind to even consider proofreading.

** One story overlaps with ConvictionByContradiction - where an inspector has an upset stomach and asks for "Bicarbonate of soda" at a bakery. When they say they don't have any, he somehow deduces they're a front since that's baking soda and no bakery would be without it. On top of all the various reasons for why the baker may not have any (they're out, he doesn't know what it means since it was called "Sodium Bicarbonate" instead), the bakery is also stated to have been one for pies - pies use baking ''powder'', not baking ''soda''. While baking soda can be used to lower the pH of acidic ingredients (such as lemons and limes), it's not often used for pies and one can easily substitute it with more baking powder since Baking Powder is just baking soda with cream of tartar.

* In a ''Literature/MikeMistMinuteMystery'' by Max Allan Collins in the early 1980s, the title character supposedly identifies a crook because she claimed that she cashed a check using an automatic teller machine, which Mike claims is impossible. The readers wrote in to note that it's done ''all the time''; you enter the value of the check into the machine as a deposit and you are free to withdraw from that amount, with the bank staff confirming the accuracy and legitimacy later on; in modern days the [=ATMs=] are smart enough they even handle the verification process.

** An alleged suicide note from a linguistics professor is determined to be a fake due to some grammatical "mistakes" that a true linguist would never make, including the use of a split infinitive such as "''to'' '''''boldly''''' ''go''"). First, correctness of split infinitives is a matter of great debate; while some do abhor them, many have no problem with them at all. Second, Sobol mixes up ''linguists'' with ''grammarians''; the former being a study of aspects of a language such as what sounds are meaningfully distinct, how it expresses things that will take place in the future, and other stuff like "is there a separate word for 'hand' vs 'arm' or do they use only one word?" while the latter being the study of restraints on words and the order they go in. Finally, that's before you have to wonder if a person ''contemplating suicide'' is in the correct frame of mind to even consider proofreading.

* An episode of ''Series/{{Columbo}}'' titled "[[Recap/ColumboS04E01 An Exercise in Fatality]]" has a key piece of evidence that a fake accident was really a murder hinge on how the victim's shoes were tied. This actually could have been reasonable evidence, except that the way the evidence is framed and explained is completely self-contradictory and counter-factual. The problems with Columbo's explanation are as follows:
** Firstly, Columbo explains that when right-handed people tie their own shoes, the big/top loop ends up over the big toe every single time -- which suggests that people tie their shoes with a different dominant hand depending on whether they're tying their right or left shoe, as opposed to using the exact same process on each foot. This is completely wrong, as any non-ambidextrous person who ties their shoes would know.
** Secondly, Columbo explains that the victim's shoes were tied with the big/top loop over the little toe, indicating that a right-handed person must have done up his shoes for him, because they would be doing their usual action backwards. The problem with this? The victim was clearly stated and shown to be left-handed, thus this supposed evidence doesn't contradict the notion that the victim tied his own shoelaces, because nothing would be "backwards" about the way his shoes were tied.

** One of the Inspector Berkovich stories[[note]]a collection of short stories for Israeli Russian speakers, with many of the stories being expansions of the Two-Minute Mysteries[[/note]] has a witness claim he saw a man being murdered while a clock was ticking -- except it was digital. The twist is; the man was completely honest; he was hearing a particular radio station which always transmitted a metronome's ticking for a few minutes before its regular broadcasts started.

** One story overlaps with ConvictionByContradiction - where an inspector has an upset stomach and asks for "Bicarbonate of soda" at a bakery. When they say they don't have any, he somehow deduces they're a front since that's baking soda and no bakery would be without it. On top of all the various reasons for why the baker may not have any (They're out, he doesn't know what it means since it was called "Sodium Bicarbonate" instead), the bakery is also stated to have been one for pies - pies use baking ''powder'', not baking ''soda''. While baking soda can be used to lower the pH of acidic ingredients (such as lemons and limes), it's not often used for pies and one can easily substitute it with more baking powder since Baking Powder is just baking soda with cream of tartar.

* One ''ComicBook/SupermansPalJimmyOlsen'' comic featured Jimmy [[WholesomeCrossdresser crossdressing]] to [[ItMakesJustAsMuchSenseInContext test the detective skills of his fanclub]]. They found him out in part because "Jackie" had tied a bowtie into a garter, to show "herself" as a member of the club, and according to them, "girls don't wear neckties and never have the practice to tie them ''that'' well." This is probably news to the millions of women who help their boyfriends, sons, or husbands with getting their ties on, not to mention the girls that have to wear ties as part of a [[CatholicSchoolGirlsRule school uniform]].

* ''Series/{{Sherlock}}'' is often guilty of this.

* ''Literature/EncyclopediaBrown'', the former TropeNamer, often bases the solution of mysteries on assertions that a certain event could not have happened as described for a particular reason. In some cases, the reason would make the event unlikely, but not impossible. Other times, the reason is simply false.

** Book 4, chapter 9 ("The Case of the Murder Man"): In the ShowWithinAShow (a two-man stage show) portrayed in the chapter, the solution to the crime lay in the fact that the murderer didn't leave prints, and "it was too hot for gloves," so they arrested the guy in gloves. Plenty of people wear gloves for all kind of reasons and in all kinds of weather.

** Book 12, chapter 5 ("The Case of the Mysterious Thief"): The case was "solved" (by Sally, not Encyclopedia) because a couple sat in a restaurant with the man's back to the wall rather than the woman's, from which Sally deduced that each was actually a member of the other gender in disguise. This is because of a rule of etiquette that the woman should sit against the wall, so she can see and be seen. For this to be evidence, it would have to be the case that people followed this "rule" with no, or at best, very few exceptions; only Sally had ever heard of it, and it was falling out of favor in the real world even when the books were published. This same solution supposes that the victim is a woman so strong only a man could've knocked her out with one punch, ignoring the fact that the victim is, well, a very strong woman, which by itself admits that very strong women exist.
::: From a meta perspective this "solution" also ignores what a big piece of the books' internal logic "girls can be even tougher than boys" really is. The canonical reason the bullies Encyclopedia outsmarts don't try to get even by just punching his teeth out is his partnership with Sally, who beats up anyone who tries. The books go so far as to actually call her his bodyguard whenever they explain this.
** Book 15, chapter 5 ("The Case of Hilbert's Song"): The solution relies on the fact that the culprit had used glycerin tears that fell from the outside corners of her eyes instead of the inside, thus revealing them to be fake, as "If only one tear falls, it will run from the inside corner of the eye, by the nose, and not from the outside corner." Only, none of that is true; how tears flow from a person's eyes is a function of the physical shape of their eyelids, nose and cheek, not to mention the orientation of the head relative to gravity's pull.