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]
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 werewolves. Or they'll just testify against you and make you go to jail. Or they want to prevent a Cycle of Revenge from happening in the most direct way.
So you have to kill everyone in the room. Or, possibly, the city.
Similar to Shoot Everything That Moves, 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.
A specific case — often invoked by otherwise-heroic characters who need to eliminate individuals who might jeopardize their mission — would be Killed to Uphold the Masquerade. People who are Trigger Happy may jump to this solution a bit more readily. See also Never One Murder. Contrast with Leave No Survivors, where you're killing everyone just out of general bloody-mindedness (or hatred). Opposed to Spare a Messenger, when you specifically leave someone alive to relate what they've just seen.
- In Berserk, Guts instinctively did this when he heard a witness after he assassinated Duke Julius on Griffith's orders. 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.
- In 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 Damsel in Distress, 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.
- Ophelia, from Claymore is big on this. Claymores aren't allowed to kill humans, but Ophelia is more than a little Ax-Crazy, so she tends to get carried away when she fights. Solution: Murder everyone who saw her.
- It's mentioned a few times that Golgo 13 will kill any witnesses to an assassination as a general rule. (Usually, though, there aren't any.)
- In an anime episode Togo has Identity Amnesia, 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 Professional Killer realises this trope will now apply. She's prepared to Face Death with Dignity, but is then 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 Death Seeker follows Togo to a job, perhaps with this trope in mind. Togo obliges despite having slept with her earlier.
- Gunslinger Girl. Cyborg girl Rico befriends a boy working as a bellhop while scoping out her target. Her 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 smiling cheerfully because she 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 highlight her handler's ruthless nature; other handlers just use the Move Along, Nothing to See Here approach.
- Kira Yoshikage in part 4 of Jojos Bizarre Adventure will use his powers to kill anyone who could potentially contribute to exposing his crimes, down to the owner of the store where he'd left a jacket to be repaired. Part 5's villain, the mafia boss Diavolo, manages to take it even further; he's so paranoid about anyone knowing anything about him that he not only kills everyone he's ever met in-person, but also spends the bulk of the story trying to assassinate his estranged daughter over the miniscule chance that someone could discover his identity through her. (Unsurprisingly, this results in a Revealing Cover Up for both of them, contributing to their defeats by the heroes.)
- Mobile Suit Gundam Wing: Referenced directly in dialog in an early episode.
"Those who have laid eyes on a Gundam shall not live to tell about it."
- This happens twice in Mother Keeper when Graham steals the identity of Graham Gregson, he kills Graham and his entire family, as well as any possible witnesses then later he kills Silas and everyone in Silas's house.
- In One Piece, 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.
- Cipher Pol 9, one of the World Government's assassination squads, cannot allow their existence to be known to the public. Their approach is to kill everyone who finds out about it or their missions. In the series, this begins with the people within the Galley-La Company they infiltrated to obtain the blueprints to one of the aforementioned horrific weapons, the Pluton. Unfortunately for them, they dragged the Straw Hat Pirates into this, who turn the situation around by not only causing enough trouble to interrupt CP9 from killing anybody in Galley-La, they follow CP9 to their headquarters and nonlethally defeat them all there and thus disgracing the squad. This results in their boss, Spandam, disbanding the entire squad and putting them on the run, at least until they get revenge on Spandam.
- After the Straw Hats defeat Gecko Moria on Thriller Bark, the World Government decide that they can't allow word of another Warlord being defeated to spread, so they order Bartholomew Kuma to kill everyone on the island. Fortunately, Zoro is able to talk him down in exchange for Zoro being made to suffer all of Luffy's pain instead.
- Vienna Salvatori, the anti-hero assassin featured in Vienna, an audio-only spin-off of Doctor Who 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.
- Asterix: In Asterix and the Secret Weapon, Caesar demands that no witnesses be left of the 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 No Quarter!" and just charges through the pirate ship, ripping it in half (which conveniently allows the pirates to survive in their rowboat since they didn't see anyone).
- Button Man: 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.
- Clue 2017: At the end of the story, Dr. Black orders Upton to clean every loose end from the plot. He proceeds to do so with brutal efficiency, including wiping out the people making the comic.
- Dinocorps: When Jarek orders his team to look for the Annihilation Trigger as stealthily as possible, a police car shows up. He doesn't hesitate to kill the cops inside to conceal his identity from the humans.
- Disney Ducks Comic Universe: In Carl Barks 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 waiting for a rescue team. Scrooge delivers the horseradish on time.
- Played for Black Humor in Les Innommables, 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 they could just as easily killed him onboard the ship, now Lychee is going to have to row them back.
- Robin (1993): In their efforts to cover up their illegal human experimentation Strader Pharmaceuticals keeps expanding the list of people they're hiring mercenaries to kill. It starts out as just trying to dispose of their victims, but expands to include the drug dealers they'd used, the investigative journalist looking into the mess and anyone else who ended up involved with their victims.
- Silent Hill: Sinner's Reward has this trope in its backstory. The mob boss Sara's father offended put a hit on Sara's father. Jack, the hit man said mob boss enlisted to eliminate Sara's father, went to Sara's residence and carried out the murder of her father, before killing her mother, too (since she was right next to her husband). On the way out, Jack encountered Sara and, not wishing to run the risk of having Sara incriminating him as a witness, murdered her as well before fleeing the scene. Sara is understandably angry once the truth is made clear.
- The Rourke family in Sin City usually ensure this when covering up the trail of bodies left by the two different Serial Killers 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 The Spirit, 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.
- Star Wars Expanded Universe:
- In Darth Vader: Dark Lord of the Sith, stormtroopers bring a captive Jedi named Jocasta Nu aboard Vader's airship. Unfortunately for the troopers, Jocasta knows Vader is Anakin Skywalker and proceeds to blurt it out in front of everyone. Vader instantly Force Shoves all the troopers out of the airship to their death.
- Star Wars (Marvel 2015): A flashback in Issue #50 reveals that when Vader recruited Queen Trios to infiltrate the Rebellion as a Double Agent on his behalf, he proceeded to kill all the servants and guards who were in the room at the time, in order to keep the plan a secret.
- Who Took the Super out of Superman?: Xviar quickly blasts to ashes two unlucky prospectors who see his spaceship landing so they cannot tell anybody that he is an alien.
- Who is Superwoman?: The titular villain is ordered to leave no witnesses during her mission to bring Reactron back to headquarters. Since Reactron is harassing his ex-girlfriend when she catches up with him, Superwoman murders the woman, making it seem like an accident.
- The Hunt for Reactron: When General Lane foists Reactron on Perseus Hazard's K-Squad, which is tasked with capturing Supergirl and her companions, he secretly orders the villain to kill both the Kryptonians and the whole K-Squad should they discover the heroes have been framed. Reactron even attempts to murder Lane's daughter Lois when she discovers him, something not even Sam Lane would have approved of.
- In The Strange Revenge of Lena Luthor, Blackrock promises to deal with a mobster who is hounding Linda Danvers' co-worker Greg Gilbert if Greg steals some blueprints from the GBS research labs... fully planning to kill Greg in order to cover his tracks.
- 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 Top 10, Comissioner Ultima will have to destroy Neopolis to prevent word of her Xenite addiction getting out.
- Wonder Woman:
- Wonder Woman (1942): A trio of gangsters decide to kill someone who just happened to overhear their insurance fraud plans, as the timing led them to believe the witness knew even more. Unfortunately for them the witness was Etta Candy, and she'd been in a hurry an willing to just ignore them and instead ends up beating them all unconscious and handing them over to the cops.
- After burying his treasure with four of his men Capt. Storm kills everyone involved and who saw them to ensure its location remains secret.
- Team Cipher encourages this in Pokémon Reset Bloodlines during their operations.
- Invoked in Arcadia or Bust. When Jim explains to Blinky how they were spotted by teenagers that thought they were conventioneers at a local Horror Convention, Blinky is quick to ask he killed them, only for a bemused Jim to affirm that he didn't.
- In Amazing Fantasy, this is the Prowler's M.O. The only reason why she's even known is because of the few Heroes who managed to survive their fights with her and failed to capture her, a list which includes All Might. This is also why Izuku is confused when she spares him and tells him to mind his own business when she could have easily killed a Quirkless kid like him.
- 21st Century Serial Killer: When Aaron and Charles see that someone witnessed them killing a bartender, they chase the guy into the kitchen. Aaron can't bring himself to shoot the witness, so Charles does it instead.
- In the opening of The American, George Clooney'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 One Last Job.
- In the 1982 Australian/Taiwanese movie Attack Force Z, a World War II 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.
- An assassin in Barracuda is tasked to kill employees of a smalltown newspaper to make sure that the Government Conspiracy 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.
- The Battleship Island: During World War 2, the Japanese island of Hashima contains a coal mine staffed by Korean conscripts. Realising that Japan is about to lose the war and that war crime charges are a possibility, the Japanese managers decide to kill all of the Koreans.
- Defied in Best Seller (1987). James Woods' character goes to a policeman-turned-novelist (Brian Dennehy), asking him to write his story as a professional hitman for a Corrupt Corporate Executive. 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, "Because I knew I'd need her some day."
- In the 1968 Italian movie Black Jesus, the Patrice Lumumba-expy is taken out to be shot 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.
- The pirates in The Black Pirate leave no witnesses by blowing up the ships they have pillaged.
- In Blastfighter, Wally and his cronies assault Tiger's friends in an attempt to scare him into leaving the poaching ring alone. However, when they attempt to rape Connie, Pete tries to intervene and Wally shoots him. Realising that he has killed him, Wally orders his men to kill everyone so there are no witnesses.
- There's a Running Gag in Burnt by the Sun of a truck driver who is lost and keeps driving around the place asking for directions. After Colonel Kotov is arrested by the NKVD they encounter this man, who recognises Kotov and is shocked to see him savagely beaten when he tries to exit the car to speak to him. The truck driver is then shot and thrown into the back of his truck.
- The Cassandra Crossing is about an express train that is de-routed from its way from Geneva to Stockholm because there is a terrorist on the train who is infected with a virus. The passengers shall instead be quarantined in a former Nazi concentration camp. The way there leads over the namesake bridge which has been closed since 1948 and is absolutely unsafe to cross. Even though the virus can easily be healed with oxygen, a U.S. military intelligence Colonel insists in sending the train into its doom. The reason is because the virus was an American bio-weapon illegally parked outside the NATO, and he has to kill everyone who may know about it.
- In the stagecoach robbery at the start of Coroner Creek, Miles Younger kills the driver, guard and all of the male passengers. He little kills all of the Indians who aided him in the robbery.
- GoldenEye has Ourumov and Xenia massacre the staff of the Bunker to ensure none of them could accuse the former of stealing the second eponymous satellite. The exceptions are Boris Grishenko, intentionally spared and offered a new job with Janus; and Natalya, who knew how to survive it.
- Heat. In the opening robbery, a psychopathic member of the gang kills a security guard for not following his instructions. Another guard draws a pistol and is also shot. The last guard doesn't resist, but the gang exchange a Meaningful Look and kill him too. As they've already committed multiple homicide, there's no incentive to leave a potential witness alive.
- Hellbound: The reason why Prosatanos kills the prostitute: he might have let her go otherwise, but she walks in on him after he just finished murdering someone else, with the bloody evidence still in his hands.
Prosatanos: Time for you to leave.
- The Iceman. 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 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.
- Judge Dredd, 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 Kill Bill, Bill and his squad kill everyone at The Bride's wedding, even "the colored fella playing the piano".
- 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.
- In Machete Kills, this is taken Up to Eleven 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.
- When it's planned that the mine is to be blown up in The Mask of Zorro, its peasant workers (including children) were also trapped to prevent witnesses.
- In Morgan, the scientists that aren't killed by Morgan are killed by Lee Weathers as damage control.
- In Universal's The Mummy (1932), when the renegade priest Imhotep is buried alive with the 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 incorporated wholesale into the 1940 Continuity Reboot, The Mummy's Hand.)
- The intro of Muppet Treasure Island 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!"
- Once Upon a Time in the West. 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]
- The phrase "Dead men tell no tales" shows up frequently in the Pirates of the Caribbean 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.
- Planet of the Apes (2001): When Thade inspects Leo's crashed space ship, he murders the two ape soldiers who found it and reported it to him.
- In RoboCop 2, the Corrupt Corporate Executives who are trying to bankrupt the city discover the Mayor is going to cut a deal with a drug lord to get the necessary funding. They send their cyborg killing machine to kill the Mayor and the criminals, 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.
- After Kirk and McCoy escape from the Rura Penthe penal colony in Star Trek VI: The Undiscovered Country, 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 The Federation. 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.
- Star Trek Into Darkness:
- Admiral Marcus has no intention of letting any of the Enterprise crew live even after Kirk pleads that he alone should be punished for his command decisions.
- Every Klingon who witnesses Harrison ends up dead.
- Star Wars:
- This is probably why the Stormtroopers slaughter the Jawas and kill Luke's aunt and uncle in A New Hope, 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 The Force Awakens, Kylo Ren has the First Order stormtroopers wipe out a whole Jakku village. Seeing how heartless it is, Finn refuses to follow along, and this soon leads to his MookFace Turn.
- In The World Is Not Enough, the Big Bad's 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.
- A con man calls a random elderly woman.
Voice: Mom, it's your son. I have run down a child. I'll need two hundred dollars.
Old Woman: Bump off the witnesses, you idiot, and get out of there! By the way, I only have a daughter.
- There are no recorded cases of fatal attacks by wild orcas on humans (this despite their other name, killer whales). Some will point out that, clearly, the orcas simply don't leave witnesses.
- An attempt at this kicks off the plot of Arctic Rising. 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.
- In The Bridge Kingdom Archives king Silas of Maridrina has everyone in the training complex killed (apart from his spymaster Serin), even mute servants and his faithful weapons master Erik, because he cannot allow anyone to learn that he's been training his daughters as warriors and spies — as this would undermine his Altar Diplomacy schemes.
- The villains of A Brother's Price are fond of hiring 'river trash' for transportation and dirty work, then killing them when it's done. Captain Tern actually sets out to track them by looking into records of ship crews who've all been killed.
- Chocoholic Mysteries: Several of the victims throughout the series are murdered because they found out what the culprit was up to, or at least part of it.
- Ciaphas Cainnote , despite being (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 Dirty Business, and they would have revealed his position and endangered a very important mission if he'd let any escape. (And from the vantage of hindsight, it's probable the specific people in his way weren't allies and that the decisiveness and thoroughness of the slaughter did represent the bare minimum of needed force.)
- 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.
- The Doctor Who 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 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...
- Egil's Saga:
- When Jarl Arnvid of Varmland sends out his henchmen to ambush Egil and his companions bringing the taxes from Varmland to King Hakon, he explicitly orders them to let no one escape and to kill them all. The plot fails, as it turns out the jarl's goons are no match for Egil.
- 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.
- 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 Gold-Bug" by Edgar Allan Poe, 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.
- 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 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 too uncertain. Though they could have saved themselves the trouble if they'd just sold the nuke instead.
- Honor Harrington:
- In the short story "A Grand Tour" by David Drake, 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 podnoughts rides to the rescue in the defence of Basilisk, Earl White Haven nearly has a heart attack when he thinks Admiral Yanakov ordered no quarter. Fortunately, the latter only called for no mercy, which is a powerful emotional statement but is thankfully not a massive war crime.note
- The quadruple murder of the Clutter family that In Cold Blood is centered around comes about because Smith and Hickock aimed to rob the Clutters and kill anyone who saw them.
- In the third book of the Knight and Rogue Series 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.
- In the third Safehold book, Merlin is forced to kill a bunch of wounded Temple Loyalists after foiling an assassination attempt against Sharleyan because he can't afford to let people realize he was even there.
- Septimus Heap: The Port Witch Coven Witch Linda intends to throw Wolf Boy to the Grim after he's fed Lucy to it so that he can't spread the information, since she's read many detective novels. It doesn't work out.
- In the novelization of Star Wars Revenge Of The Sith, 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 Treasure Island, Captain Flint killed the sailors who helped him bury the treasure. This is Standard Operating Procedure in pirate tales.
- The Way of Kings (first book of The Stormlight Archive): 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.
- Blake's 7. In "Volcano", Servalan has secretly landed on a neutral planet, and orders two men sent to her with a message from a local traitor killed so they won't tell anyone of their presence. In fairness the stakes were pretty high, as there was a Doomsday Device on the planet which the locals had threatened to detonate if the Federation attempted a landing.
- The Boys (2019):
- The series starts with Hughie seeing his girlfriend being killed by A-Train, a member of The Seven. The Vought Corporation, who funds The Seven, spins the death as a tragic accident, but Billy Butcher, who is plotting to take down The Seven, tells Hughie that Supes actually kill a lot more people as Collateral Damage with only a few cases, like Hughies' girlfriend, going public. The reason no one knows about this is because the Vought Corporation is very good at covering up their misdeeds, and generously compensates relatives of their victims so they'll keep quiet.
- In episode four, following the botched rescue attempt of a hijacked plane over the Atlantic Ocean, Maeve begs Homelander to rescue at least a woman and her daughter, but Homelander say they'll just tell the world how they left everyone else to die. She reluctantly puts them down, and as they float thousands of feet over the ocean, they see the plane going down in the distance.
- Breaking Bad:
- "Dead Freight" has Walter, Jesse, and the new Nice Guy 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 on a dirt bike 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. End of episode.
- Discussed Trope earlier on. While planning the same train heist, Mike notes that they will be forced to kill the crew if they go in guns blazing, remarking that "I've been in this business long enough to know there are two types of heists: those where they get away with it, and those that leave witnesses". Jesse initially solved the problem by suggesting a diversion so as not to alarm the engineers and replacing the stolen methylamine with waternote , they just weren't expecting a random kid to show up in the middle of the desert.
- Appears to be the Standard MO for Dead Larry in Burn Notice.
- In the CSI episode "Code Blue Plate Special", a low-grade hitman hired by one of the co-owners of a diner to kill his brother (the other co-owner) kills everyone in the diner due to his mask being ripped off before being killed himself by the man who hired him.
- Doctor Who:
- "Voyage of the Damned": The robotic Host aboard the spaceship Titanic kill any surviving passengers and crew they can find after the ship is hit by meteors because their boss' plan to crash the ship requires this, so it seems accidental.
- "Partners in Crime": Miss Foster kills Stacey Campbell by converting her into Adipose after Stacey accidentally witnesses one being created from her body fat. Foster, however, does not realize until it's too late, despite the Doctor's attempt to save her, that her employers consider her a witness as well...
- In the Firefly episode "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 helps the prisoners escape.
- The first episode of Game of Thrones concludes with 10-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, as the true parentage of the future king is an important plot point). When he's spotted, Cersei just keeps saying, "He saw us!" until her brother shoves Bran out the window. Bran survives this fall, but loses the use of his legs and his memory of the event, which is not discovered by the Starks until much later.
- The Gifted (2017): In the second episode of Season 2, Reeva orders the Frost sisters and her other minions to kill everyone who works at the factory where Lorna gave birth to her daughter in the previous episode, in order to cover their tracks in case of any potential investigation.
- The Grand Tour: 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!
- Kingdom Adventure: The moment Zordock realizes the kids saw him arranging the murder of the Prince, he orders them to kill the kids, too.
- Played for Laughs in a Dead Pet Sketch done on Mad TV. The pet-sitter "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, the water-delivery man, then calls in a passing jogger under increasingly implausible circumstances... then finds out that the parrot was just stunned. And then proceeds to kill it.
- The Professionals.
- In "Heroes", several citizens foil the robbery of an armored car (actually a disguised political assassination). Because one of the criminals was partially unmasked during the raid, Cowley decides to tell the press that the man can now be identified, in the hope of flushing out the criminals who have gone to ground. Unfortunately a newspaper has published the names and addresses of these heroic citizens, so CI5 has to scramble to protect them when the criminals start murdering them.
- In "Everest Was Also Conquered", a former intelligence officer makes a Deathbed Confession that he murdered a witness to a corruption inquiry in the 1950's. As Bodie and Doyle investigate, they find they're in a race against a hitman who's killing off the other conspirators in the murder.
- Atia sends her hired man Timon to murder her daughter's former husband Glabius. Glabius asks for his servants to be spared, but Timon refuses as Atia can't afford to have her daughter finding out an apparently random act of street violence was actually her doing.
- Averted when Titus Pullo becomes a hired killer for Erastes Fulman. An old lady sees him and runs after his shouting, "Murderer!" Pullo goes to stab her but can't go through with it, suffering a Villainous Breakdown where hallucinations of old women condemn him for his crime. Next time we see him, he's been captured and put on trial.
- Leaving no witnesses is standard procedure for The Network in 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.
- The subject of the first verse and chorus of "Bird Song" by Florence + the Machine.
- In The Bible, Jacob's daughter Dinah is raped by a Schechemite prince, and her brothers 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 Disproportionate Retribution, others would see it as Combat Pragmatism; 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.
- Also from the Bible: In 1st Samuel, when David and his men temporarily sold their services to a Philistine lord, they would make raids upon the Geshurites, the Girzites, and the Amalekites. They would make a point to leave no survivors in those raids because they didn't want any witnesses testifying in Gath to what David had done to those people, to maintain the illusion of being a true defector.
- From the Gothic History of Jordanes:
- When the Visigothic King Alaric died 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 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.
- Tacitus in his Germania mentions the religious practices of the Suevi tribes, which includes there being a sacred isle containing a holy chariot that can only be touched by the priest. Well, until the slaves must wash it after the ceremony in a secret lake, that is. These slaves cannot bring back their experience of the lake, because they are drowned in the lake when they're done. As Tacitus remarked, "Hence all men are possessed with mysterious terror; as well as with a holy ignorance what that must be, which none see but such as are immediately to perish." Incidentally, among these Suevi tribes were the Angles, the namesake of England and the English language.
- Battle for Wesnoth: In the penultimate scenario of Delfador's Memoirs, Delfador needs to take back Book of Crelanu from Queen Asheviere's family demesne. Since he can't get any support from the King, Delfador's solution is to raid the place with help from the elves using orcish weapons and kill everyone there so no one could tell the king about his involvement.
- Often an explicit mission objective in City of Villains.
- Committing a crime in The Elder Scrolls V: Skyrim gets you a bounty. Killing everyone who saw said crime erases it.
- In Fire Warrior 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 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 Ghost Trick, the murderous motive of the blue foreigners is to kill everyone connected to Temsik, so they are the only ones who know about the meteorite's powers.
- In The Godfather 2 there may be witnesses to your crimes. You can run away, intimidate them into silence... or just kill them.
- 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.
- Half-Life. The Marines aren't there to rescue the scientists. Then they find out they're not high clearance enough to be left alive either..., courtesy of the Black Operations.
- The final mission of Hitman: Blood Money features Agent 47 reviving at his own funeral and killing everyone who saw him do it (including an innocent priest and a reporter), and, in the process, 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.
- Katana ZERO: The samurai assassin is specifically ordered to leave no witnesses during their assassination missions. This usually equates to killing an entire building of mooks just to get to one guy. Eventually, he rebels because one of his missions is to take out a dead scientist's family on the off-chance that he told them anything.
- In The Legend of Zelda: Breath of the Wild, the White-Maned Lynel's Compendium entry says the reason there are so few eyewitness accounts of them is because White-Maned Lynels won't let even a single passerby escape with their lives. This isnt actually borne out in-game, where Lynels are the only type of monster that dont immediately attack when they notice you.
- During the Novaria mission in Mass Effect, 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, who asks if he'll get a "you know too much" speech. Indeed this is Saren's modus operandi, as your teammate Wrex can tell you — he was once hired by Saren, along with a bunch of other mercenaries, to help raid a ship. Something about Saren gave him a bad feeling, so he left without waiting to be paid. In the following months, every other mercenary involved wound up dead.
- Naked Snake gets told this early on in Metal Gear Solid 3: Snake Eater. 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 nothing really comes of it if you ''do'' kill everyone, mostly because of the way the story is ultimately framed).
- Later in the series we learn that Operation Snake Eater had a cleaner following Snake, who dealt with any loose ends after Snake infiltrated and compromised the area. From what we know about Skull Face, he didn't leave much to chance. Or anything, for that matter.
- In Spec Ops: The Line CIA agent Riggs believes that if word got out of how the Damned 33rd, a U.S. Army Battalion, went rogue and set up a military dictatorship after their rescue mission in Dubai ended in failure, the rest of the Middle-East would declare war on the U.S., a war the U.S. would lose. To prevent that from happening, Riggs decides to recruit the protagonist into stealing and destroying the city's remaining water supply to ensure that anyone still in Dubai will have died of thirst long before any other rescue attempts into the city would be made.
- Splinter Cells 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.
- From a mission in Star Wars: The Force Unleashed: "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.
- If an NPC sees you attacking another NPC in Vampires Dawn 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.
- In World of Warcraft: 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.
- If an NPC sees you committing murder in Yandere Simulator, 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 Game Over.
- Happens multiple times in Ace Attorney, and is also often brought.
- Joe Darke was a spree killer in the first game. He accidentally hit and killed a woman with his car, which was seen by a witness. He panicked and killed the witness, only for some unlucky sap to come along and witness that, and so on, and so on...
- Apollo Justice:
- Kristoph Gavin's motive for killing Drew Misham, Zak Gramarye and attempting to kill Vera Misham, is that all three had information about him requesting forged trial evidence.
- In episode three, the real killer tries to kill 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 Up to Eleven in Ace Attorney Investigations 2, where it's revealed that the Big Bad was chased by Blaise Debeste's men for 12 years because he was a witness to the SS-5 Incident.
- In Fate/stay night, 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 The Masquerade. Even a battle to the death between magi and their Servants can be interrupted by the need to eliminate a witness.
- In Blue Yonder, the team coming after the capes kills any civies in the area.
- Darths & Droids handles this well in this strip.
- Girl Genius:
- The Order of the Stick:
- Redcloak, when 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 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, 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 who made a perfect copy of the phylactery and was killed by Tsukiko because he was in her way.
- 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. It would come back to bite them in a practical manner much later. The creator of the spell, being a Neutral Evil (with a strong emphasis on "evil") necromancer, apparently never even considered that people other than relatives might seek revenge.
- Redcloak, when 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 he would have had to kill him himself. Then he buries the location with an earthquake.
- Unsounded: When the magical weapon of mass destruction Bell is financing went off and destroyed a building and made a mess Bell has his loyals in the military destroy the whole town, hunting through it to pick off any survivors. This was also partially because a number of them were on his payroll, through intermediaries, and he planned to pin the whole mess on them.
- In the Springhole article about writing believable cover-ups and masquerades, Syera points out that this would be a bad idea for a secret organization to do, as this trope often fails to address that the witnesses in question have families and friends that will do anything to bring their killers/kidnappers to justice, and that mysterious disappearances out of nowhere will not be ignored in real life (at least if the victim is from a privileged majority).
- Part of the Achievement Hunters modus operendi when pulling a 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 Ryan is only to happy to do. Winds up being justified in Jack's heist: The one time one of them decides to spare their victim, the clerk pulls out a shotgun and blows him away as soon as his back is turned.
- Counter Monkey: The episode "Shadowrun: The Code" revolves around Spoony's recounting of an absurdly Stupid Evil team of shadowrunners that tried to pull off a heist, which devolved into a hostage situation, and then the runners decided to massacre all of the hostages anyway and blame it on this trope. It was at this point that Spoony, as the game master, finally had enough of them, went in full Killer Game Master mode, and unleashed the Night City Police's "Psycho Squad" on the team.
- Ravage of Beast Wars was sent as an agent to apprehend Big Bad 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' plans.
- In episode eight of The Boys: Diabolical, we learn the origin of Homelander's policy of doing this in the parent series — Black Noir silenced the last hostage of Homelander's original, horrifically botched mission and told Homelander exactly what to say so as to keep their reputations intact.
- In the 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.
- Spoofed in King of the Hill, where Dale tells Hank to dispose of the witnesses to a minor accident.
- The Simpsons, 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: You mean the revolver, sir?
Burns: Precisely. Be sure to wipe your own memory clear when you've finished.
- Star Wars: The Clone Wars: In "Rising Malevolence", the Separatists have a new secret weapon, and they've been ensuring there are no survivors to its attacks. Obi-Wan notes that they're being "unusually tidy", and the episode make it clear that Count Dooku does not want the Republic to find out what it is.
- Star Wars Resistance: In "The Children from Tehar", the First Order is hunting the titular children because they're the sole survivors of a genocide they committed, and they don't want them escaping and telling anyone else.
- Taken to an extreme in Young Justice, the Reach scientist is concerned 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.