History Main / JustOneLittleMistake

* ''Literature/EncyclopediaBrown'' was this, aimed at kids.
* The talk between Harry and Voldemort in the end of ''Literature/HarryPotterAndTheDeathlyHallows''. Paraphased it goes something like this. "You made just one little mistake! You didn't know that [[spoiler:the ownership of the unbeatable wand transferred from Dumbledore to Draco Malfoy, and from him to me, giving me instant victory in this duel]]!"

* In ''Manga/DeathNote'', both L and Near deduce very quickly that Light must be Kira. The rest of the series they spend trying to get Light to make Just One Little Mistake. [[spoiler:Which he eventually does.]]

* In the ''Series/MidsomerMurders'' episode "Faithful Unto Death", the killer plants evidence of her crime in her friend's purse right before Detective Barnaby gives TheSummation, then wryly asks him if he has any evidence. He tells her that he had searched that same purse shortly before she arrived, then looks in the purse and pulls out the evidence, prompting her to incriminate herself. On the way out, he admits that [[InvokedTrope he was bluffing]].

* ''Film/{{Clue}}'': In both the second alternate and official ending of the film, Wadsworth was able to figure out that [[spoiler:Mrs. Peacock]] was the one who murdered the cook, because [[spoiler:she knew the cook was Mr. Boddy's accomplice in his blackmail against her]]. He explains that [[spoiler:Mrs. Peacock]]'s mistake was at dinner, [[spoiler:she]] at one point said that what they were eating was one of [[spoiler:her]] favorite recipes.

* Australia's "Lesbian Vampire Killer", Tracey Wigginton, was only caught because she accidentally dropped her credit card.

* Just as it happened in ''Film/AmericanGangster'', Frank Lucas got onto Richie Roberts' radar because of the extravagant clothes he wore to the Ali vs Frazier fight.
* The Watergate scandal came to light after a nightwatchman noticed a piece of tape on a door in the Watergate complex, removed it, came back later, and noticed it had been reapplied.

The accused looks down in bewilderment, and it's clear to the audience that he's the murderer. Just when you might expect him to break down, confess and launch into a MotiveRant, he looks up confidently, laughs, and calmly comes back with...

* ''Series/{{Castle}}'' is fond of this. They'll get the suspect pinned down (usually in the interrogation room, sometimes not), and Castle will explain what happened. The suspect will smirk, say something like "That sounds like a very good story, something out of one of your books," and then Beckett will pull out the witness statement or DNA evidence or whatnot and the smirk fades.

* ''Film/MissionImpossible'': The moment in which Ethan Hunt starts to suspect that [[spoiler:Jim Phelps [[FakingTheDead is still alive]] and [[TheMole is responsible]] for the frame job that has put him on the run for the whole film]] is when he opens the Bible he took from the Prague safe-house [[spoiler:and sees the "Placed by the Gideons in the Drake Hotel - Chicago" stamp on it, recalling Phelps' mention of going to that hotel the day before the Prague op]].

[[folder:Film—Live-Action]]

* Australia's "Lesbian Vampire Killer", Tracey Wigginton, was only caught merely because she accidentally dropped her credit card.
* James Earl Ray, the murderer of Martin Luther King Jr., intended to flee to apartheid-ruled Rhodesia, which besides treating blacks like Ray thought they should, also had the added attraction of not having an extradition treaty with the US. He made it to Canada, then to Britain, and then to Portugal, one of the few countries in the world with diplomatic relations with Rhodesia and, through its colony in Mozambique, also a long border with it. Unfortunately for Ray, the guy who forged his Canadian documents wrote his surname as "Sneyd" in his birth certificate, and "Sneya" in his passport, and the Portuguese sent him back to Britain. Upon arrival he was recognized as the now infamous Ray, arrested and extradited to stand trial in Tennessee.

* The Watergate scandal came to light after a nightwatchman noticed a piece of tape on a door in the Watergate complex, removed it, came back later and noticed it had been reapplied.

* While Ted Bundy had already been named as a suspect in his serial killings due to his similarity with a suspect sketch and having the same car model, he only started having problems when he run a stop sign and was pulled over by a traffic cop. The cop then found a mask, gloves, a crowbar, handcuffs, and other items likely to be used in a home invasion inside his car.

* ''Series/{{Matlock}}'': Ben Matlock ''loves'' pulling this trick on suspects he knows he's got beat by making it appear as if he hasn't got a thing on them to convict them of their crime, luring them into a false sense of security. Ultimately, he reveals that he has all the evidence necessary to incriminate them. One time, Ben actually goes out of his way to explain that one must be incredibly careful in planning out a murder because the tiniest mistake will trip up the culprit.