History Main / LockedRoomMystery

* The ''Machinima/RedVsBlue'' episode "Grey vs Grey" features this, with a DeliberateMonochrome to give it that ''film noir'' appeal. (Also, to illustrate that all of the characters are colorblind) Essentially, a Red Team and a Blue Team unrelated to the main characters seal themselves in a room to broker a truce. The lights go out, a gun goes off, and one of the soldiers winds up dead and the rest need to figure out who shot him. [[spoiler: The narrator reveals that the victim actually died of a heart attack before the shot was fired.]]

** ''Literature/TheLightFantastic'': An ''accidental'' locked room killing - a wizard near death sought to hold off the the Reaper by sealing himself behind a series of powerful wards to protect him from any possible threat, but forgot the implications of the fact that one of the protective barriers was airtight.

** In "Reunion, and Turnabout", your assistant is locked in an empty room with the victim, a gunshot is heard, and the door is opened to reveal her standing over the corpse with a smoking gun in her hand. Naturally, [[CourtroomAntic it now falls on you to prove her innocent in court]]. [[spoiler: The killer was impersonating your assistant.]]

** ''VisualNovel/DanganronpaV3KillingHarmony'' has two of these mysteries in a single case. One victim is found with a stab wound through their neck, inside a room that was bolted from the inside. [[spoiler:The killer stabbed the sword they'd used to kill her into a hanging sculpture of Kaede Akamatsu, then twisted the rope on the statue so that it would spin on release, the sword's hilt pushing the bolt shut.]] The other victim is somehow stabbed in the neck [[spoiler:while crouching inside a cage, with a sheet and an 8kg statue on top]], with several other people present. [[spoiler:The killer rigged the floorboard the victim was crouching on to act as a seesaw, so she could be propelled upwards into the blade, which had been planted inside the cage.]]

** In "Reunion, and Turnabout", your assistant is locked in an empty room with the victim, a gunshot is heard, and the door is opened to reveal her standing over the corpse with a smoking gun in her hand. Naturally, [[CourtroomAntic it now falls on you to prove her innocent in court]].
** "Turnabout Big Top" involves a man found dead in the middle of a snow-covered courtyard with only one set of footprints leading to the body... and an eyewitness who saw the killer leave the murder scene by ''flying over the rooftops''.

** ''VisualNovel/DanganronpaV3KillingHarmony'' has two of these mysteries in a single case. One victim is found with a stab wound through their neck, inside a room that was bolted from the inside. [[spoiler:The killer stabbed the sword they'd used to kill her into a hanging sculpture of Akamatsu, then twisted the rope on the statue so that it would spin on release, the sword's hilt pushing the bolt shut.]] The other victim is somehow stabbed in the neck [[spoiler:while crouching inside a cage, with a sheet and an 8kg statue on top]], with several other people present. [[spoiler:The killer rigged the floorboard the victim was crouching on to act as a seesaw, so she could be propelled upwards into the blade, which had been planted inside the cage.]]

* ''Literature/JaineAustenMysteries'': A very minor one not related to the murder in ''Death of a Bachelorette''. No matter what Jaine does (including getting a bolt installed on her door), Prozac keeps escaping from her room. It's revealed [[spoiler:she was escaping via a hole in the wall hidden from sight by Jaine's bed.]]

** Some episodes turned this UpToEleven, with Steve Wagner being in outer space at the time of the murder in "Mr. Monk and the Astronaut", while Brian Babbage managed to commit murder while ''in a coma'' in "Mr. Monk and the Sleeping Suspect". [[spoiler:Notably, both cases involved using the mail service as a time delay. The astronaut noosed his drugged victim to a garage door and mailed the opener to the house, the coma victim glued mail bombs to the insides of public mailboxes so they would be picked up days later. Brian Babbage also was originally planning to be arrested and locked up in jail when his bombs went off, but accidentally ended up in a coma.]]

** The fourth murder of ''VisualNovel/DanganronpaTriggerHappyHavoc'' is presented as one of these, with the victim alone in a room with the door jammed shut to the point that the protagonist had to break open a window on the door to get it open. [[spoiler: Eventually subverted; the victim committed suicide. The locked room was to prevent anyone else being blamed for her death.]]

** The fourth murder of ''VisualNovel/DanganronpaTriggerHappyHavoc'' is presented as one of these, with the victim alone in a room with the door jammed shut to the point that the protagonist had to break open a window on the door to get it open. [[spoiler: Eventually subverted; the victim committed suicide.]]

* The fourth book of the ''Literature/IrishVillageMysteries'' , ''Murder in an Irish Pub'', has poker player Eamon Foley found in the storeroom of a pub hanging from a rope. The door is locked from the inside and Foley seems to have a suicide note in his pocket. [[spoiler: The killer locked the deadbolt by hooking a tentpole around it through a small window. The "suicide note" is actually an autograph Foley gave to a fan.]]

* Randall Garrett used this trope often in his Literature/LordDarcy stories, with the added twist that magic is real in Darcy's world. Magicians naturally become prime suspects in a Locked Room Mystery, yet Lord Darcy often works out a non-magical explanation, thus exonerating some innocent wizard of the crime.

* In one episode of ''Anime/SuperSonicTheAnimation'', Sonico is found unconscious inside her locked dressing room with her guitar missing, and her bandmates, with the help of a KidDetective, have to try and uncover who did it and how. [[spoiler:Subverted when it turns out that that the room was never locked in the first place; the culprit just ''pretended'' it was in order to throw everyone off.]]

* One of the Detective Cilan episodes of ''{{Anime/Pokemon}}''. Despite the door being locked and the outside being guarded by a Watchog, and the jewel under lock and key, the power goes off and the Liepard's Eye is stolen. Several clues point to {{Red Herring}}s, but Cilan eventually covers the truth: the man Ash battled in the tournament earlier in the episode purposely used an Electric type in their match to short circuit the power to cause a distraction, and had his [[ChekhovsGunman Vanillite]] sneak into the room through a vent, make a key out of ice, and steal the jewel. The perp's role in the tournament would also serve as an alibi, since he'd be too busy battling Ash to steal the gem.

* In the first ''VideoGame/PaperMario'' game, Mario discovers the corpse of Mayor Penguin, with the name "Herringway" written on a piece of paper in his hand, in a room that, while it technically isn't locked, his wife was standing in front of the only entrance. Naturally everyone thinks Mario did it. [[spoiler:He isn't actually dead. He merely fell and knocked himself unconscious while trying to retrieve a present for his friend Herringway from a high shelf.]]

** Again in the TV-movie ''El misterio del asesino inesperado'': a man is found dead inside his office, with a gunshot, but the weapon is nowhere to be seen and nobody is around. The door was locked from the inside and the windows were shut. [[spoiler:He knew he had been poisoned and someone wanted to frame Laura's son, so he called Laura and told her he was going to lock himself, commit suicide with a non-immediately-lethal shot, throw the gun out the window and shut it. All she had to do was stand under the window to collect and then get rid of the weapon to complete the 'impossible' murder, which would both seem impossible to solve and distract from the poison, as the murder method was obviously the gun.]]

** Again in the TV-movie ''El misterio del asesino inesperado'': a man is found dead inside his office, with a gunshot, but the weapon is nowhere to be seen and nobody is around. The door was locked from the inside and the windows were shut. [[spoiler:He knew he had been poisoned and someone wanted to frame Laura's son, so he called Laura and told her he was going to lock himself, commit suicide with a non-immediately-lethal shot, throw the gun out the window and shut it. All she had to do was stand under the window and get rid of the weapon to complete the 'impossible' murder, which would both seem impossible to solve and distract from the poison, as the murder method was obviously the gun.]]

** Again in the TV-movie ''El misterio del asesino inesperado'': a man is found dead inside his office, with a gunshot, but the weapon is nowhere to be seen and nobody is around. The door was locked from the inside and the windows were shut. [[spoiler:He knew he had been poisoned and someone wanted to frame Laura's son, so he called Laura and told her he was going to lock himself, commit suicide with a non-lethal shot, throw the gun out the window and shut it. All she had to do was stand under the window and get rid of the weapon to complete the 'impossible' murder, which would both seem impossible to solve and distract from the poison, as the murder method was obviously the gun.]]

A seemingly impossible crime. The standard example being that of a murder victim found in a room with only a single door, securely locked from the inside. Can be the basis for a single plot, or an entire show. A well-designed Locked Room Mystery provides pleasure from trying to figure out the puzzle before it is revealed, from moments of dawning realisation, and from a satisfyingly logical solution. A poorly designed Locked Room Mystery only provides a feeling of having been cheated. Contrary to the name, Locked Room Mysteries don't necessarily have to be murders or take place in locked rooms, just to be crimes that seem to be impossible at first glance (e.g. contemplating how it's possible for someone to travel from one part of the island to another within minutes). The question of ''who'' is rarely as interesting in this kind of plot as ''how''.

* ''Manga/DetectiveConan'' frequently uses these, though it also plays with this trope, as Conan solves a case when he realizes that a man died [[spoiler: the moment his wife checked on him (he was drugged into sleep until then)]], but the rest of the room was set up to make it look like a locked room mystery.

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* In ''Film/TheVerdict'' (1946) Sydney Greenstreet plays a Scotland Yard inspector forced to retire after his investigation sends an innocent man to the gallows. Soon after that the nephew of the victim in the first case is found stabbed to death in his bed in a locked room that Greenstreet had to force open. [[spoiler: Actually the man was still alive (but drugged) and Greenstreet stabbed him to death after forcing open the door. He covered his actions by screaming that the man was already dead, causing the landlady to recoil in horror, missing his actions. The Inspector murdered the man for two reasons. First he realized that the man had murdered his aunt for her money and let an innocent man hang for it. Also he hoped that his arrogant successor at Scotland Yard would never solve the case, humbling him. In the end he had to confess to the crime to prevent another innocent man from being hanged for murder.]]

* In "The Verdict" (1946) Sydney Greenstreet plays a Scotland Yard inspector forced to retire after his investigation sends an innocent man to the gallows. Soon after that the nephew of the victim in the first case is found stabbed to death in his bed in a locked room that Greenstreet had to force open. [[spoiler: Actually the man was still alive (but drugged) and Greenstreet stabbed him to death after forcing open the door. He covered his actions by screaming that the man was already dead, causing the landlady to recoil in horror, missing his actions. The Inspector murdered the man for two reasons. First he realized that the man had murdered his aunt for her money and let an innocent man hang for it. Also he hoped that his arrogant successor at Scotland Yard would never solve the case, humbling him. In the end he had to confess to the crime to prevent another innocent man from being hanged for murder.]]