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[[quoteright:300:[[ComicBook/CrimeDoesNotPay http://static.tvtropes.org/pmwiki/pub/images/leave_no_witnesses_9.jpg]]]]

->'''Team Leader:''' There's no sign of Dredd. He appears to have survived the crash.\\
'''Judge Griffin:''' ''[over the radio]'' You are in error, Capture Team. No one survived the shuttle wreck. Understand? Just find Dredd!\\
'''Leader:''' The pilot, sir. He's alive.\\
'''Griffin:''' ''[over the radio]'' No one survived the shuttle wreck! Do I make myself clear?\\
'''Leader:''' Yes, sir. ''[shoots the pilot]''
-->-- ''Film/JudgeDredd''

Sometimes you just can't afford to be seen. Everybody needs to believe you're dead. Or they saw you use superpowers, or now they know there are such things as vampires. Or they'll just testify against you and make you go to jail.

So you have to kill everyone in the room. Or, possibly, the city.

Similar to ShootEverythingThatMoves, but that trope is more about the situation where everything you see is a threat. In ''this'' case, people would be more than happy to leave you alone, but that just doesn't seem to be an option anymore.

Oh, by the way, if you're a {{Mook}} and you've been ordered to kill all the witnesses, one thing to keep in mind: [[YouHaveOutlivedYourUsefulness As far as your boss is concerned]], [[HeKnowsTooMuch you're a witness, too.]]

A specific case - often invoked by otherwise-heroic characters who need to eliminate individuals who might jeopardize their mission - would be KilledToUpholdTheMasquerade. People who are TriggerHappy may jump to this solution a bit more readily. See also NeverOneMurder. Contrast with LeaveNoSurvivors, where you're killing everyone just out of general bloody-mindedness (or [[FinalSolution hatred]].) Opposed to SpareAMessenger, when you specifically leave someone alive to relate what they've just seen.



[[folder:Anime & Manga]]
* It's mentioned a few times that Manga/Golgo13 will kill any witnesses to an assassination as a general rule. (Usually, though, there aren't any.)
** In an anime episode Togo has IdentityAmnesia, and only remembers who he is just before the assassination. The beautiful woman who saved his life and stuck with him this far without knowing he's a ProfessionalKiller realises this trope will now apply. She's prepared to FaceDeathWithDignity, but is then [[BadGuysDoTheDirtyWork killed by a stray bullet from one of the bad guys]] before we discover if Togo will spare her.
** However in another episode a woman who's become a DeathSeeker follows Togo to a job, perhaps with this trope in mind. [[ConsummateProfessional Togo]] obliges despite having slept with her earlier.
* [[TheOphelia Ophelia]], from ''Manga/{{Claymore}}'' is big on this. Claymores aren't allowed to kill humans, but Ophelia is more than a little AxCrazy, so she tends to get carried away when she fights. Solution: Murder everyone who saw her.
* In ''Manga/{{Berserk}}'', Guts instinctively did this when he heard a witness after he assassinated Duke Julius on Griffith's orders. [[spoiler:He realized too late that it was the Duke's young son, whom Guts empathized with earlier. It's implied that Griffith hoped this would happen, since the boy was being groomed to marry Princess Charlotte, who Griffith had designs on.]]
* ''Manga/GunslingerGirl''. Cyborg girl Rico befriends a boy working as a bellhop while scoping out her target. Her [[TheHandler handler]] Jean orders Rico to kill anyone who sees her committing an assassination. While leaving the hotel room after the hit, she runs into the boy and in one of the more memorable scenes of the series kills him while [[CreepyChild smiling cheerfully]] because she [[MoralMyopia remembered the right words to use in a situation like this]]; "I am sorry." However this is the only example of this trope in ''GSG'' and is used more to [[KickTheDog highlight her handler's ruthless nature]]; other handlers just use the MoveAlongNothingToSeeHere approach.
* In ''Manga/OnePiece'', the World Government attempted to kill anyone with knowledge of the Void Century or the ability to read the dominant language used during that time (as indestructible tablets exist in that language that tell what happened). While they couldn't kill everybody with such knowledge, they've killed most of them, and the remaining ones would rather keep quiet to stay alive. This is because horrific weapons capable of destroying the entire planet were made during that century, and the World Government considers it better to kill off anyone with even the slightest chance of harnessing them than global annihilation. It's implied that there's also information from the Void Century that would undermine the World Government's political power, giving them perhaps an even greater motivation.
** During the Dressrosa arc, once the spell that's turned most of Dressrosa's citizens turned into toys is undone, exposing Donquixoite Doflamingo as the villain he is, Doflamingo's Plan B is to KILL EVERYONE, so that they won't be able to tell the rest of the world.
* This happens twice in ''Manga/MotherKeeper'' when [[spoiler: Graham steals the identity of Graham Gregson, he kills Graham and his entire family, as well as any possible witnesses]] then later [[spoiler: he kills Silas and everyone in Silas's house]].
* Referenced directly in dialog in an early episode of ''MobileSuitGundamWing'': "Those who have laid eyes on a Gundam shall not live to tell about it."
* In ''Manga/Brave10'', the ninjas chasing Isanami made a fatal mistake when they chose to follow this order while pursuing Isanami. Saizo wasn't too interested in saving a DamselInDistress, but telling him they'll kill him because he's seen too much is just an invitation to prove his ninja cred with their blood.

[[folder:Audio Plays]]
* Vienna Salvatori, the anti-hero assassin featured in ''Vienna'', an audio-only spin-off of ''Series/DoctorWho'' produced by Big Finish Productions, has a rule that anyone who hears her real name has to be killed. The Doctor appears to be a rare exception.

[[folder:Comic Books]]
* In ''ComicBook/TopTen'', [[spoiler:Comissioner Ultima]] will have to destroy Neopolis to prevent word of [[spoiler:her Xenite addiction]] getting out.
* The Rourke family in ''ComicBook/SinCity'' usually ensure this when covering up the trail of bodies left by the two different {{Serial Killer}}s connected to them; even going so far as to try to kill children or lowlifes like Marv. Both of these targets end up being their own undoing, however.
* In ''ComicBook/{{Asterix}} and the Secret Weapon'', Caesar demands that no witnesses be left of the [[WouldntHitAGirl titular secret weapon]] (since it would not only be seen in Rome as dishonorable but also ridiculous). When pirates threaten the secret ship, the leader announces "Caesar said no witnesses, so NoQuarter!" and just charges through the pirate ship, ripping it [[IncrediblyLamePun in half]] (which conveniently allows the pirates to survive in their rowboat since they didn't see anyone).
* In ''Terra Obscura'', the Grim Reaper puts his costume on in a cab, having hailed it in street clothes to avoid suspicion, as he tails someone targeted for a hit. The first thing he does when he's got the target in his sights is kill the cabbie, who saw his unmasked face.
* In ''Comicbook/TheSpirit'', two bank robbers take this approach to cover their crime. They don't realize they missed a little girl down the block, who fell down out of fear. The police are a bit peeved.
* In Creator/CarlBarks story "The Horseradish Story", [=Scrooge McDuck's=] ancestor failed to deliver a case of horseradish to Jamaica. Chisel [=McSue=], as the last heir of the person who hired Scrooge's ancestor to make the delivery, takes advantage of this fact to claim Scrooge's fortune. To keep his money, Scrooge must recover the horseradish from the bottom of the ocean and deliver it to Jamaica within 30 days. When it seems Scrooge will triumph where his ancestor failed, Chisel and a thug named Joe assault his ship. When it seems Scrooge and the horseradish will be lost forever, Chisel tries to get rid of Joe as well to be sure that nobody will testify against him. Joe escapes and Chisel joins Scrooge and his family into [[spoiler:waiting for a rescue team. Scrooge delivers the horseradish on time.]]
* Played for BlackHumor in ''ComicStrip/LesInnommables'', after Colonel Lychee and the Dog-Man take member of the Dog-Man's crew ashore to see if a buried treasure exists. Lychee shoots the man once they find it, and tells the disgruntled-looking Dog-Man that he could have told someone else about it. The Dog-Man then points out [[BadBoss they could just as easily killed him onboard the ship]], now Lychee is going to have to row them back.
* ''ComicBook/ButtonMan'': After Harry kills another Button Man disguised as an FBI agent in a motel, Ugly John investigates the scene and kills the clerk who witnessed this too.

[[folder:Films -- Animation]]
* A creepy exchange in ''WesternAnimation/MonstersInc'':
-->'''Waternoose:''' Get up! There can't be any witnesses.\\
'''Randall:''' There won't be.

[[folder:Films -- Live-Action]]
* ''Film/JudgeDredd'', in the page quote. After a shuttle carrying prisoners to Aspen Penal colony crashes, a rescue/capture team is sent to locate Dredd, a convict on the flight. The Capture Team Leader reports to Judge Griffin; Judge Griffin spells it all out.
* In Creator/{{Universal}}'s ''Film/TheMummy1932'', when the renegade priest Imhotep is buried alive with the [[MacGuffin Scroll of Thoth]], the slaves who dug the tomb are killed -- then the spearmen who killed them are killed, so there will be no witnesses. (This sequence was [[StockFootage incorporated wholesale]] into the 1940 ReBoot, ''Film/TheMummysHand''.)
* In ''Film/KillBill'', Bill and his squad kill ''everyone'' at The Bride's wedding, even "the colored fella playing the piano".
* In the 1968 Italian movie ''Black Jesus'', the Patrice Lumumba-expy is taken out to be shot [[WhatDoYouMeanItsNotSymbolic along with two criminals]]. After he's executed one of the criminals says, "Don't worry, I didn't see anything". The executioner replies, "Yes, but you ''heard'' something" and shoots him when he turns to run.
* When it's planned that the mine is to be blown up in ''Film/TheMaskOfZorro'', its peasant workers (including ''children'') were also trapped to prevent witnesses.
* In ''Film/RoboCop2'', the {{Corrupt Corporate Executive}}s who are trying to bankrupt the city discover the Mayor is going to [[DealWithTheDevil cut a deal with a drug lord]] to get the necessary funding. They send their cyborg killing machine to kill the Mayor, specifically stating that there must be no witnesses. Ironically the Mayor is the only one to escape the subsequent massacre, but can't afford to admit what he was up to anyway.
* ''Film/GoldenEye'' has [[TheHeavy Ourumov and Xenia]] massacre the staff of the Bunker to ensure none of them could accuse the former of stealing the [[spoiler:second]] eponymous satellite. The exceptions are [[TheCracker Boris Grishenko]], intentionally spared and offered a new job with Janus; and [[BondGirl Natalya]], who was GenreSavvy enough to know how to survive it.
* In ''Film/TheWorldIsNotEnough'', the BigBad[[spoiler:'s [[TheDragon Dragon]]]] Renard gets himself a Russian nuclear submarine. He brings along "some refreshments" for the crew. By the time Bond gets on the sub, the crew are all dead from the poison.
* After Kirk and [=McCoy=] escape from the Rura Penthe penal colony in ''Film/StarTrekVITheUndiscoveredCountry'', they find out that their guide was paid to do that, so that the escapees could be shot by the guards without any questions raised by TheFederation. When the guards catch up to them, the guide is shot by the warden, uttering this trope name. He's about to kill the two humans (after telling them who ordered the hit), when they are beamed up.
* ''Franchise/StarWars'':
** This is ''probably'' why the Stormtroopers slaughter the Jawas and kill Luke's aunt and uncle in ''Film/ANewHope'', seeing as they are trying to leave evidence that Tusken Raiders did it.
** Likewise, after Darth Vader attacks Leia's ship (a ship containing an emissary of the Galactic Senate), he orders a subordinate, "Send a distress signal, and inform the Senate that all on board were killed." Presumably he wants to make it look like the ship was destroyed by random piracy, and left nobody alive who could contradict that story.
** In ''Film/TheForceAwakens'', Kylo Ren has the First Order stormtroopers wipe out a whole Jakku village. [[HeelRealization Seeing how heartless it is]], Finn refuses to follow along, and this soon leads to his MookFaceTurn.
* The pirates in ''Film/TheBlackPirate'' leave no witnesses by blowing up the ships they have pillaged.
* ''Film/StarTrekIntoDarkness'':
** [[spoiler:Admiral Marcus]] has no intention of letting any of the ''Enterprise'' crew live even after Kirk pleads that [[TakeMeInstead he alone should be punished]] for his command decisions.
** Every Klingon who witnesses Harrison ends up dead.
* In ''Film/MacheteKills'', this is taken UpToEleven with the assassin El Chameleon, who kills ''anyone'' who sees him, even when he's just taking a walk down the street. This is even though he has the ability to change his face and body to look like anyone.
* ''Film/{{Killshot}}'': Blackbird has a policy of killing anyone who sees his face during his kills. This is because of a prior hit that went wrong when his brother let a nurse who witnessed them go freely, who then sounded an alarm. When he is hired by the mafia to kill an old criminal, he goes off-plan by also killing the woman who let him in as she could identify him. The pissed off mob boss who hired him puts a prize on Blackbird's head because the woman was his mistress.
* An assassin in ''Film/{{Barracuda}}'' is tasked to kill employees of a smalltown newspaper to make sure that the GovernmentConspiracy stays hidden. He kills the people who know too much, and tries to quietly get out the room when an another person discovers the corpses. Unfortunately, she turns around and he has to kill her too.
* In the opening of ''Film/TheAmerican'' Creator/GeorgeClooney's character is out walking with a girlfriend when he's targeted by an assassin. Clooney kills the assassin to the shock of the woman, who's surprised that he even carries a gun, but he just yells at her to go and call the police. As she turns to leave, he shoots her in the back of the head. The kill weighs on his mind and fuels his eventual desire to make this OneLastJob.
* ''Film/OnceUponATimeInTheWest''. One of the earliest evil deeds Frank does is kill a child after this sinister excerpt of dialogue:
-->'''Goon:''' ''[about the boy]'' What are we gonna do with him, Frank?\\
'''Frank:''' ''[beat]'' Well, now that you've called me by name -- ''[shoots the child]''
* ''Film/TheIceman''. After Kuklinski kills a pornographer, he finds a seventeen-year old girl hiding in his closet. He hauls her out onto the street and it's at that point he meets fellow hitman "Mr Freezy" Pronge for the first time, who tries to run her down with his [[BadHumorTruck ice cream truck]]. Kuklinski makes Pronge cease his pursuit at gunpoint, but when the two hitmen team up later on, the first thing Pronge shows him is the girl's body, which he has kept frozen for later disposal.
* The phrase "Dead men tell no tales" shows up frequently in the ''Franchise/PiratesOfTheCaribbean'' films. The writers, in a bit of an ''esprit de l'escalier'' moment, say they should have used it for Jones' line here.
-->'''Maccus:''' What of the survivors?\\
'''Jones:''' There are no survivors.
* Defied in ''Film/BestSeller'' (1987). James Woods' character goes to a policeman-turned-novelist (Brian Dennehy), asking him to write his story as a professional hitman for a CorruptCorporateExecutive. To prove his claim, he brings the writer to the maid who let him into the house where he killed a senator. When Dennehy's character asks why this witness is still alive, the hitman replies, "[[CantKillYouStillNeedYou Because I knew I'd need her some day]]."
* In the 1982 Australian/Taiwanese movie ''Attack Force Z'', a UsefulNotes/WorldWarII commando force encounter a villager and ask for directions to their objective, then shoot him with a silenced submachine gun so he won't tell anyone of their presence on the Japanese-occupied island.
* In ''Film/{{Morgan}}'', the scientists that aren't killed by Morgan are killed by Lee Weathers as damage control.
* The intro of ''Film/MuppetTreasureIsland'' shows Captain Flint and a band of pirates lugging several treasure chests up on Treasure Island to bury them. When they chests are in the pit and the pirates start to cover them, Flint draws his guns on his crew and fires. The intro song ends simultaneously on the fitting line "Dead men tell no tales!"

* In ''Litarature/TreasureIsland'', Captain Flint killed the sailors who helped him bury the treasure. This is Standard Operating Procedure in pirate tales.
* Literature/CiaphasCain[[note]]'''HERO OF THE IMPERIUM!'''[[/note]], despite being ([[BlackAndGrayMorality more or less]]) a good guy, orders this done to what he himself calls "a virtually defenseless ally" in ''For the Emperor''. To his credit, he's very disturbed by the need for such DirtyBusiness, and they would have revealed his position and endangered a very important mission [[ShootTheDog if he'd let any escape]].
* The ''Series/DoctorWho'' spin-off novel ''The Eyeless'' features an alien superweapon that turns out to be part of an extremely thorough attempt to remove all witnesses: not only did they kill the witnesses, they destroyed the entire planet they were on and then ''every other planet that could see that planet through telescopes or whatever''.
* Subverted in the first ''Literature/{{Dune}}''; a search party was supposed to find and kill the two perpetrators and witnesses to Paul and Jessica's killing, but they were already dead when they were found...
* Two "men's adventure" novel series by Joseph Rosenberger, ''The Death Merchant'' and ''COBRA'' feature characters with a very extreme moral compass who often follow the "leave no witnesses" rule to protect their identity. The lead character in ''Death Merchant'' has a policy of killing people who learn his real identity, friend or foe, and in ''COBRA'' the "heroes" even go so far as to kill local law enforcement to protect their mission.
* In the third book of the ''Literature/KnightAndRogueSeries'' the wreckers kill anyone who has even the slightest chance of having seen them. Michael is almost killed just for noticing them off in the distance while they're discussing plans.
* ''Literature/SeptimusHeap'': The Port Witch Coven Witch Linda intends to throw Wolf Boy to the [[KrakenAndLeviathan Grim]] after he's fed Lucy to it so that he can't spread the information, [[GenreSavvy since she's read many detective novels]]. It doesn't work out.
* The villains of ''Literature/ABrothersPrice'' are fond of hiring 'river trash' for transportation and dirty work, then killing them when it's done. [[HypercompetentSidekick Captain Tern]] actually sets out to track them by looking into records of ship crews who've all been killed.
* In the third Literature/{{Safehold}} book, Merlin is forced to kill a bunch of wounded Temple Loyalists [[spoiler: after foiling an assassination attempt against Sharleyan]] because he can't afford to let people realize he was even there.
* ''Literature/TheWayOfKings'' (first book of ''Literature/TheStormlightArchive''): {{Inverted}}. Szeth is explicitly ordered to leave behind witnesses when he assassinates the governments of various countries, facilitating his master's mission of sowing chaos.
* An attempt at this kicks off the plot of ''Literature/ArcticRising''. Anika and her partner get a radiation signature off a tramp freighter and approach, assuming it's illegal waste dumping. Then the crew shoots them down with an RPG, killing her partner, and assassins are crawling out of the woodwork to try to kill her.
* ''Literature/HonorHarrington'':
** In the short story "A Grand Tour" by Creator/DavidDrake, during the brittle pre-war peace between Manticore and the People's Republic of Haven, a Havenite cruiser manned by the figurative scrapings of the Dolist masses engages and destroys a Manticoran destroyer in a back-world sector of the Solarian League. In order to keep word from getting out of their action they attempt to slaughter the crew that escaped the destroyer's destruction, missing a shuttle of survivors in the debris from the destroyed ship.
** In ''Echoes of Honor'', when the combined Grayson-Manticore fleet with the new [[MacrossMissileMassacre podnoughts]] rides to the rescue [[spoiler:in the defence of Basilisk]], Earl White Haven nearly has a heart attack when he thinks Admiral Yanakov ordered [[SinkTheLifeboats no quarter]]. Fortunately, [[SubvertedTrope the latter only called for]] no ''mercy'', which is a powerful emotional statement but is thankfully not [[UsefulNotes/TheLawsAndCustomsOfWar a massive war crime]].[[note]]For the uninitiated, "no mercy" means the attacking force will not be picking up survivors. "No ''quarter''" means they will not be ''allowing'' any.[[/note]]
* The German spy in ''Eye of the Needle'' by Ken Follett murders several people for this, always saying, "You saw my face". Later he discovers that British Intelligence has gotten hold of a photograph of him when he lived in Germany, causing him to freak out because now they really do know his face.
* In the novelization of ''Literature/RevengeOfTheSith'', when Bail Organa witnesses the clone troopers kill a Padawan on the Jedi Temple landing deck, they try to kill him too, and he barely escapes. This is in contrast to the film, where they let him go without much of a fuss.
* In ''The Golden Rendezvous'' by Alistair Maclean, the villains stealing gold from a vessel in mid-ocean plan to obliterate all evidence and witnesses with a [[NukeEm tactical nuclear weapon]] (which they've also stolen), the justification being that it would take too long to kill the passengers and crew individually, while ordinary explosive (which they do have as a back-up in case the bomb doesn't go off) is [[NoOneCouldSurviveThat too uncertain]]. Though they could have saved themselves the trouble [[CutLexLuthorACheck if they'd just sold the nuke instead.]]
* ''Literature/EgilsSaga'': Living out his life in the house of Grim, the aged Egil rides out at evening, accompanied by two slaves and carrying his two chests of silver with him. He does not return for a whole night, and in the morning returns without the silver and without the slaves, revealing that he has hidden the treasure and that he has killed the slaves to keep the secret.
* In "The Gold-Bug" by Creator/EdgarAllanPoe, the narrator and his fellow treasure hunters succeed in finding the treasure of Captain Kidd. They dig up two human skeletons immediately above the treasure chest, and infer that the dead men were Kidd's companions who helped him bury the chest, and that Kidd murdered them so he would be the only one to know the location of the treasure.

[[folder:Live-Action TV]]
* In the ''Series/{{Firefly}}'' episode "[[Recap/FireflyE09Ariel Ariel]]", the blue-gloved operatives come to pick up River and Simon from the Alliance police who've arrested them. When the lead policemen mentions that they'd talked to the prisoners, the operatives kill every policeman involved in the arrest in the loudest and most gruesome way possible, which actually [[NiceJobFixingItVillain helps the prisoners escape]].
* Possibly subverted in ''Series/{{Lost}}'' when [[spoiler: Michael kills Libby]].
* Appears to be the Standard MO for [[RunningGag Dead Larry]] in ''Series/BurnNotice''.
* PlayedForLaughs in a DeadPetSketch done on ''Series/MadTV''. The pet-sitter [[http://youtu.be/3iqSIkunnz4 "accidentally" kills his friend's parakeet]] by flinging it to the floor after it bit him, then kills the friend he was house-sitting for during the fight over the police being called. He then accidentally kills his friend's visiting mother while trying to keep her quiet, then kills the cable-guy, the mailman, [[OverlyLongGag the water-delivery man, then calls in a passing jogger]] under [[ContrivedCoincidence increasingly implausible circumstances]]... then finds out that the parrot was [[Series/MontyPythonsFlyingCircus just stunned]]. [[NotInFrontOfTheParrot And then proceeds to kill it.]]
* Leaving no witnesses is standard procedure for The Network in ''Series/{{Utopia}}''. It allows them to distort the truth in whatever capacity they see fit. The definition of "witness" can (and usually does) extend to members of their own organization.
* ''Series/BreakingBad'' has Walter, Jesse, and the new NiceGuy Todd robbing a train with methylamine. The entire thing goes off without a hitch and ends with the three celebrating the success...until they look behind them and see a 13-year old kid watching them. After a wave from the kid and a few seconds of staring, cue Todd pulling out his gun and casually shooting the kid. [[WhamEpisode End of episode.]]
* ''Series/TheGrandTour'': While most of the occupants of the airliner containing their VIP hostage in "Operation Desert Stumble" were mannequins, May ensures that their departure is at least unseen.
--> '''Clarkson:''' Are all the terrorists dead back there?
--> '''May:''' ''Everybody's'' dead back there.
--> '''Clarkson:''' Good man!
* The first episode of ''Series/GameOfThrones'' concludes with ten year-old Bran Stark climbing a tower where he witnesses Queen Cersei having sex with her own brother (this is not only incest but treason). When he's spotted, Cersei just keeps saying, "He saw us!" until her brother [[WouldHurtAChild shoves Bran out the window]].

* The subject of the first verse and chorus of "Bird Song" by Music/FlorenceAndTheMachine.

[[folder:Myths & Religion]]
* In Literature/TheBible, Jacob's daughter Dinah is raped by a Schechemite prince, and her brothers [[RapeAndRevenge kill him for it]]. They also kill all the other men of the city, and take the women and children as plunder. Some would see this as DisproportionateRetribution, others would see it as CombatPragmatism; killing the other Schechemites leaves no men to avenge the prince (and in this time and place, apparently no women willing or able to take vengeance either.) Either way, Jacob worried that someone would take revenge on him and/or his sons for their action.
* From the ''Gothic History'' of Jordanes:
** When the Visigothic King Alaric dies in Southern Italy, the Visigoths bury him with much treasure in a grave dug by a band of captives in the bed of the river Busento. Then they put all the diggers to death, so "that none might ever know the place".
** At the death of [[UsefulNotes/AttilaTheHun Attila]], the Huns have him buried during the night (for reasons of secrecy) together with treasure of various kinds, and afterwards kill all who were involved with the construction of the tomb as a precaution against grave robbers.

[[folder:Video Games]]
* ''Videogame/HalfLife''. The marines aren't there to ''save'' the scientists. Then they find out they're not high clearance enough to be left alive either.
* From a mission in ''VideoGame/TheForceUnleashed'': "The Emperor must not discover your presence. Kill everyone aboard, Imperials and Kota's men alike."
** Given that you don't really have an option (they all shoot at you), it's not that difficult. In fact, many of them can be killed by standing still. Your character will automatically redirect their blaster shots back at them.
* In ''VideoGame/GhostTrick'', the murderous motive of [[spoiler:the blue foreigners]] is to [[spoiler:kill everyone connected to Temsik, so they are the only ones who know about the meteorite's powers]].
* The final mission of ''VideoGame/HitmanBloodMoney'' features Agent 47 [[spoiler:reviving at his own funeral and killing everyone who saw him do it (including an innocent priest and a reporter)]], and, in the process, [[RoaringRampageOfRevenge taking his revenge]] on the people who've been screwing him over for the entire game. The mission objective is given as the trope name.
* Often an explicit mission objective in ''VideoGame/CityOfVillains''.
* In ''VideoGame/FireWarrior'' the Space Marines sent to kidnap the Ethereal were ordered to do this. One repeats "no witnesses" before stomping the head of an unfortunate Tau.
* In the ''Silent Threat'' expansion for ''[[VideoGame/FreeSpace FreeSpace: The Great War]]'' begins with a mission in where you have to cover up a skirmish that occurred between Terran and Vasudan ships by killing everyone who saw it.
* In VideoGame/WorldOfWarcraft: Cataclysm, the Goblins fleeing Kezan wind up in a firefight. The humans don't want witnesses, so they blow up the Goblin ship, leaving them shipwrecked on the Lost Isles.
* Naked Snake gets told this early on in ''VideoGame/MetalGearSolid3SnakeEater''. Actually doing so is ill-advised, as it makes a later boss fight harder. (It's actually more of a directive to remain unseen, rather than kill everyone)
** The actual ''Snake Eater'' mission goes out of its way to subvert this: if you leave ''no'' witness or evidence of US involvement in the mission, then Russia won't be able to prove that the US cleaned up the mess it created. So you ''have'' to leave some people alive (though [[GameplayAndStorySegregation nothing really comes of it if you ''do'' kill everyone]], mostly because of the way the story is ultimately framed).
* ''[[VideoGame/GoldenEyeWii GoldenEye Reloaded]]'' mirrors the film in the Bunker part of the Severnaya mission where Ourumov tells his men to "''leave no survivors''" for the same reason as in the film. Boris Grishenko is absent entirely, but Natalya is instead saved by Bond in this version of the story.
* Committing a crime in ''VideoGame/TheElderScrollsVSkyrim'' gets you a bounty. Killing everyone who saw said crime erases it.
* In ''VideoGame/TheGodfather 2'' there may be witnesses to your crimes. You can run away, intimidate them into silence... or just kill them.
* If an NPC sees you attacking another NPC in ''VideoGame/VampiresDawn'' you can't leave the area until you've killed them. Abraxas averting this trope by letting Valnar live after their first encounter becomes a plot point in ''Reign of Blood''.
* If an NPC sees you committing murder in ''VideoGame/YandereSimulator'', they will either run off the school grounds to contact the police or to their favorite teacher to bring them to the body. If you manage to cover up for your crime, they'll spread rumors about your being a murderer, causing continuous damage to your reputation until they are dealt with.
** Students with the "Heroic" personality ''must'' be disposed of: if they see you commit a murder, they will attempt to restrain you. If you fail the struggling minigame or are caught when you're not holding a weapon, they'll pin you to the ground, thus resulting in a GameOver.
* During the Novaria mission in ''VideoGame/MassEffect'', Saren tries to cover up what he's been doing there by having everyone who was involved with the project killed. You arrive just in time to save the last surviving scientist, [[GenreSavvy who asks]] if he'll get a [[HeKnowsTooMuch "you know too much"]] speech. Saren apparently makes a habit of this, as your teammate Wrex can tell you- he was once hired to help raid a ship by Saren, along with a bunch of other mercenaries. But something about Saren rubbed him the wrong way, so he left without waiting to be paid and was the only mercenary there who survived.
* '''VideoGame/SplinterCell''''s are explicitly told that "a choice between leaving a witness or a corpse is no choice at all", with the implication that the Cells must remain completely unknown in order to retain their deniability. In-game, there's never a situation in which killing a civilian is acceptable, however.

[[folder:Visual Novels]]
* In ''VisualNovel/FateStayNight'', the magi try to hide their abilities from normal people in order to avoid persecution. It's generally accepted as a fact of life among magi that any non-magus who sees them using their powers must die to maintain TheMasquerade. Even a battle to the death between magi and their Servants can be interrupted by the need to eliminate a witness.
* Happens multiple times in ''Franchise/AceAttorney'', and is also often brought.
** Joe Darke was a serial killer in the first game. He hit and killed a woman with his car, then panicked and started killing everyone who was a witness.
** ''{{VisualNovel/Apollo Justice|Ace Attorney}}'':
*** [[spoiler:Kristoph Gavin]]'s motive for killing Drew Misham, Zak Gramarye and attempting to kill Vera Misham, is that all three had information about him [[spoiler:requesting forged trial evidence]].
*** In episode three, the real killer tries to kill [[spoiler:Lamiroir]] to silence her from revealing important information about their crime.
*** The Judge mentions that it was brave of Wesley Stickler to shout out at the killer whom he saw pointing a gun at the victim, because killers normally don't want to leave witnesses behind. Stickler himself obviously didn't consider this when trying to stop the murder and gets rather distraught over this fact.
** Quite possibly taken UpToEleven in ''VisualNovel/AceAttorneyInvestigations 2'', where it's revealed that the BigBad was chased by [[spoiler:Blaise Debeste's men]] for '''12 years''' because he was a witness to [[spoiler:the SS-5 Incident]].

[[folder:Web Comics]]
* In ''Webcomic/BlueYonder'', [[https://web.archive.org/web/20150920183814/http://www.blueyondercomic.net/comics/1043248/blue-yonder-prologue-page-9/ the team coming after the capes kills any civies in the area.]]
* ''Webcomic/GirlGenius'':
** Jägers [[http://www.girlgeniusonline.com/comic.php?date=20031017 discuss]] this topic. "Dis is turnink into vun of ''[[NeverOneMurder dose]]'' plans..."
** Included in the difference between a good magician and an evil magician, [[http://www.girlgeniusonline.com/comic.php?date=20070115 as described by]] Master Payne.
* ''Webcomic/TheOrderOfTheStick'':
** Redcloak, when [[spoiler: destroying the Resistance and retrieving back Xykon's phylactery]], uses monsters he summoned, allowing him to simply send them back to their planes. He also doesn't resurrect the hobgoblin spy he used, and is thankful that he died in the battle, or [[HeKnowsTooMuch he would have had to kill him himself.]] Then he buries the location with an earthquake.
--->'''Redcloak:''' ...The exact details here need to remain between me and our god.
** A few strips later, [[spoiler:after Tsukiko discovers too much about Redcloak's manipulations, he takes control of her wights and has them kill and eat her. He then orders them to eat each other, and for the last one remaining after that to set himself on fire.]] Right after this, he disintegrates the body of the hobgoblin [[spoiler:who made a perfect copy of the phylactery and was killed by Tsukiko because he was in her way.]]
** [[spoiler:Vaarsuvius']] use of the Familicide spell, given that it was cast to ensure that nobody related to the target in question would ever come seeking revenge. [[spoiler:It would come back to bite them in a practical manner much later.]] The creator of the spell, being a NeutralEvil (with a strong emphasis on "evil") necromancer, apparently never even considered that people other than relatives might seek revenge.
* ''Webcomic/DarthsAndDroids'' handles this well in [[http://www.darthsanddroids.net/episodes/0686.html this strip]].

[[folder:Web Original]]
* Part of the ''Creator/AchievementHunter''s modus operendi when pulling a [[LetsPlay/AchievementHunterGrandTheftAutoSeries heist]] is to always kill the clerk, cashier or teller they are robbing afterwards, as well as any bystanders who happen to be nearby; something [[TokenEvilTeammate Ryan]] is only to happy to do. Winds up being [[JustifiedTrope justified]] in [[spoiler:Jack]]'s heist: The one time one of them decides to spare their victim, [[NoGoodDeedGoesUnpunished the clerk pulls out a shotgun and blows him away as soon as his back is turned]].

[[folder:Western Animation]]
* Spoofed in ''WesternAnimation/KingOfTheHill'', where Dale tells Hank to dispose of the witnesses to a minor accident.
* In the WesternAnimation/{{Chowder}} episode, Chowder's Catering Company, after Schnitzel walks in on Chowder disobeying one of Mung's orders, Chowder knocks him out with a shovel and hides him in a pickle barrel. When Mung sees Chowder with the pickle barrel (Note: Mung doesn't know that Schnitzel is in the barrel.), he knocks him out as well. Then Truffles comes in, he knocks her out as well. Fortunately, Chowder lets them all out just as he's about to throw them down a pit.
* ''WesternAnimation/TheSimpsons'', when Lisa unearths what looks like an angel:
-->'''Lisa:''' It could be anything, it could be a mutant from the nuclear plant.\\
'''Burns:''' D'oh! Fiddle-faddle, everyone knows our mutants have flippers. Oh! I've said too much. Smithers, use the amnesia ray.\\
'''Smithers:''' [[DeadlyEuphemism You mean the revolver, sir?]]\\
'''Burns:''' Precisely. Be sure to wipe your own memory clear when you've finished.
* Taken to an extreme in ''WesternAnimation/YoungJustice'', the Reach scientist is concerned [[spoiler:when the Reach is finally exposed as invaders and lose their invitation to Earth since it means the Green Lantern Corp will be able to target them. Black Beetle figures there won't be any evidence of a treaty violation if Earth is destroyed. Black Beetle is willing to kill ''billions'' to cover his tracks.]]
* Ravage of ''WesternAnimation/BeastWars'' was sent as an agent to apprehend BigBad Megatron and offers to aid the Maximals in returning home afterwards. In reality, as Megatron himself guesses, his real orders were to kill everyone on prehistoric Earth to avoid anyone back on Cybertron learning of his bosses' [[MakeWrongWhatOnceWentRight plans]].