A highly publicized crime has just been committed, with the criminals bearing distinguishing marks that make them easy for the general public to recognize if they see them out on the street. Unfortunately, those distinguishing marks are also generic enough for ''anyone'' who has similar features to be mistaken for the criminal.

Usually, when this happens, the person(s) who mistook the innocent person for the perp will overreact, and either call the cops and/or go after the suspect themselves. Or, in a similar vein, the mistaken-for-perp performs an action that, to a police officer or passers-by, seem suspicious and paramount to guilt in the crime, even though in reality the action was meant to be innocuous or even helpful to the situation. Either way, HilarityEnsues... unless played straight, in which the victim of the mistaken identity is either beaten to death by a vengeful mob or wrongly imprisoned.

A more general superset of MistakenForMurderer.

The trope name comes from the old saying "Guilt by association", which itself invokes the real-life charge of accessory to the crime, but is separate from GuiltByAssociationGag in that someone is punished along with a group despite not actually having anything to do with the crime and is generally a comedy trope.

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!!Examples

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[[folder: Comic Books ]]

* ''ComicBook/{{Watchmen}}'': Nite Owl is a LegacyCharacter. The original Nite Owl went public and wrote a book after his retirement from being a superhero. The current Nite Owl, whose identity is never publicly known, helps break Rorschach out of prison during a prison riot. A street gang wants to get revenge on him for that and they [[spoiler: assume that the publicly-known Nite Owl is the one who did it, so they break into his house and kill him]].
* In the original ''[[Comicbook/TeenageMutantNinjaTurtlesMirage Teenage Mutant Ninja Turtles]]'' comics, April and the turtles once got chased by the police because April's van coincidentally was the same make, model, and color as a van used by a group of bank robbers earlier that day.

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[[folder: Film ]]

* In ''Film/{{M}}'', the scare over the child killer is so great that one completely innocent man gets attacked by an angry mob just for speaking to a child. Vigilantism was something that bothered the director, Creator/FritzLang; his first American film, ''[[Film/{{Fury1936}} Fury]]'' (1936) stars Spencer Tracy as an innocent man who's nearly killed by a lynch mob-- but in what could be a case of HeWhoFightsMonsters, he attempts to frame ''the entire mob'' (or at least the 22 people shown in newsreel footage of the crime) for succeeding in his murder.
* In ''MasterOfTheFlyingGuillotine'', the eponymous villain goes on a vendetta after a one-armed boxer killed his disciples, murdering every one-armed man he stumbles across.
* Inverted in ''Out of Time''. An older white woman who was a witness to a crime describes a black man to a sketch artist and then points out the chief of police (and, coincidentally, the man she saw at the crime scene) as being the culprit. After a tense pause, she starts pointing out every black man in the station which discredits her testimony, and marks one of many close calls for the protagonist while he tries to slow down the investigation that is leading straight to him.
* ''ComicBook/VForVendetta'' had V send copies of his mask to virtually the entire population of London. StateSec overreacted when children started wearing them, resulting in even more of a backlash from the people against the government.
* A 1940 ''Film/TheBatman'' serial really goes over the top with this. The masked villain gets a distinctive cut on the back on his hand while getting away...and suddenly ''three'' major characters are sporting them, and the mystery of who he is is kept alive a bit longer.
* This forms the plot of the Creator/AlfredHitchcock film ''Film/TheWrongMan''. Manny Balestrero, a musician at New York City's Stork Club, so resembles a man who had twice held up an insurance office that police are called when Manny unknowingly goes there on business. He is arrested after several witnesses identify him as the robber, and in providing a handwriting sample he misspells a word which was also misspelled in a note written by the robber.

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[[folder: Literature ]]

* ''Literature/TheWheelOfTime'': After Rand announces himself as the Dragon Reborn, it's mentioned that anyone in the area who is remotely similar to his description (young, male, red hair, tall) is at risk of being attacked.
* In the {{Sten}} series, there was operation Nightfog, a purge of military personnel who'd been conspiring to bring down the [[CorruptCorporateExecutive Council]] which usurped TheEmpire:
-->There were, of course, mistakes.\\
A writer of children's fiche named White, much loved and respected, was unfortunate to live in the same suburb as a retired major general named Whytte. The writer's house was broken into in the middle of the night. The writer was dragged to the center of his living room and shot. The writer's wife tried to stop the killers. She was shot as well.\\
When the mistake was revealed, the head of the murder unit ... thought the matter an excellent joke.
* In ''ASongOfIceAndFire'', after [[spoiler: Tyrion is framed for poisoning Joffrey]], Cersei offers a huge reward to anyone who brings her the head of her dwarf brother Tyrion, which leads to a steady stream of people bringing her the heads of innocent dwarves and the occasional child. The murders go unpunished because Cersei doesn't want anyone to hesitate if they actually do find Tyrion and aren't entirely certain of his identity.
* A lighthearted version features in ''[[AuntDimity Aunt Dimity Digs In]]'': several people see two hooded figures in the vicinity of the vicarage the night [[spoiler: an old pamphlet is stolen from the vicar's desk]]. Throw in fog, lights, and a crop circle, and HilarityEnsues.

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[[folder: Live Action TV ]]

* An episode of ''Series/{{CSI}}'' involved the beating death of a taxi driver by an angry mob after he supposedly ran down a young kid. Not only was the kid already dead when the taxi rolled over him, but the driver -- whom the mob assumed was getting back into the taxi to drive away -- was actually reaching for his CB radio to call in the accident.
* Justified in an episode of ''DrakeAndJosh'' -- Josh not only resembles the Theater Thug, he was hired to play the criminal on "America's Most Wanted". Is it any wonder people kept trying to get him arrested?
** But for the police to arrest him [[spoiler:when he's being attacked by the ''real'' Theater Thug?]]
* There was a TV Show on PBS a while back about thrift stores and other ways to get cool used stuff. To start the journey, the show's hosts bought a retired ambulance on eBay to cart their findings around in. Several weeks into production, some terrorists stole an ambulance. Within a month, they had been pulled over by, interrogated by, and gotten signed statements from troopers in at least three states attesting that it was not these guys. Not that any of the troopers believed the previous ones, of course.
* In many ''Series/DoctorWho'' stories, the Doctor arrives in an environment (e.g. research base, spaceship, space station) shortly after sinister events have begun occurring, usually including deaths. The person in charge (e.g. commander, director of research) assumes the Doctor and companion/s did it. (Admittedly, under the circumstances, that's often not so unreasonable.) Then the Doctor and companion/s are opposed by the people they're trying to help, as well as the actual villain/s.
* A fifteen year old boy (at the time) in ''Series/{{Flashpoint}}'' was accused and sentenced for raping and murdering a classmate of his, being the last person to see her and [[spoiler: the lawyer against him faking a witness that he had confessed to the crime, so the case could be wrapped up.]]
* One episode of ''Series/TheMysteryFilesOfShelbyWoo'', Shelby and friends were trying to figure out who stole jewelery from a safe and became very suspicious of a magician who the spotted trying to conceal a small box on the porch. Once confronted, he began looking very guilty and his wife started to cry. Turns out he was on a diet and was sneaking food behind her back.

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[[folder: Theatre ]]

* In both Creator/WilliamShakespeare's play ''Theatre/JuliusCaesar'' and in reality, Cinna the Poet was murdered by a mob due to his shared name with one of Caesar's assassins. This was ironic, historically, as he was a friend and supporter of Caesar, but Shakespeare introduced some black comedy by having a member of the mob comment that even if this Cinna isn't the guilty one, [[DisproportionateRetribution being a bad poet is reason enough to kill him]]. This was something of a TakeThatMe in the original production, where Cinna the Poet was played by Shakespeare himself.

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[[folder: Video Games ]]

* Actually averted in ''VideoGame/FireEmblemTellius''. Sothe gets no suspicion cast upon him by any characters, despite the group finding out there's a spy on the ship the chapter he joins.

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[[folder: Western Animation ]]

* This happens to Groundskeeper Willie in ''WesternAnimation/TheSimpsons'' episode "The Great Money Caper".
* In an episode of ''WesternAnimation/TheBoondocks'', Tom, a criminal prosecutor, is arrested for supposedly resembling the X-Box Killer.

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[[folder: Real Life ]]

* For a while in the 1999's & 2000's, any young person who wore a trenchcoat was more often than not accused of being part of the legendary "Trenchcoat Mafia", a presumption made famous from the (equally erroneous) accusation that the perps in the Columbine High School shootings were part of the gang (which the Trenchcoat Mafia technically were not).
* Occasionally, it's been reported that actors that work for shows like ''Unsolved Mysteries'' and ''America's Most Wanted'' have the police called on them by people who, having seen the reenactments, presume they're the criminals they're portraying.
** This happened often enough that America's Most Wanted started notifying the authorities in the area where the actors lived so that they wouldn't get arrested.
* Lets not forget the good old Paedophile witch hunts in the UK no so long ago, resulting from the publication of a sex offender list in a national newspaper. It was unfortunate for those who had similar names or addresses to the accused.
** This has been repeated of late with the "No Fly" lists in the US; people who are so dangerous they cannot be let on a plane under any circumstances, yet haven't actually done anything bad enough to warrant investigation or arrest. If you shared a name with someone on that list, flying would take on a whole new dimension of fun.
** People have also been kept from voting in certain states if their name was similar to one on a list of convicted felons. This was one of the controversies with the Florida ballots in the 2000 presidential election.
* This is supposedly why the GunmanWithThreeNames trope exists -- to prevent people with two out of the three names of the killer from being accidentally arrested or victimised.
** Journalism students are taught to be very specific about accused criminals with generic names, adding either an address or middle initial.
* During the famous [[http://en.wikipedia.org/wiki/Beltway_sniper_attacks Beltway Sniper attacks]], pretty much the only evidence the police had to go on was that a white van was seen at the crime scenes. People immediately started to report every time they saw a white van; it's actually been suggested the flood of false leads hampered the case.
* On September 5, 1921, SilentFilms comedian Creator/FattyArbuckle was giving a party in a UsefulNotes/SanFrancisco hotel room when actress Virginia Rappe's uterus began to hemorrhage. She died four days later. Arbuckle was charged with murdering her. (It's been theorized that her uterus hemorrhaged due to several back alley abortions.) Unfortunately for Arbuckle, Mary Pickford's sister-in-law, Olive Thomas, had accidentally ingested a solution of bichloride of mercury on September 5, 1920, and died five days later. (Thomas's husband, Jack Pickford, had syphilis. Bichloride of mercury was then commonly used as a topical treatment for the sores.) The fact that Rappe fell ill on the one-year anniversary of Thomas's accidental poisoning did not go unnoticed by the MoralGuardians of the time. The scandalous deaths of Rappe, Thomas and several other silent film stars in the early 1920s were among the factors that led to the adoption of UsefulNotes/TheHaysCode in the 1930s.

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