A convenient way to deal with someone you want dead is to simply not save their life when a situation arises in which their death is inevitable.
Killing is messy. You have to deal with those pesky murder charges, or go to the effort of engineering a convenient "accident" or "suicide" to avert suspicion, or clean up the crime scene to hide your involvement. But as fate would have it, if your foe winds up in a fatal position and you are their only means of survival, all you have to do to kill them... is nothing at all.
In Real Life, this concept is called the duty to rescue. According to The Other Wiki, the failure to offer help for those in need isn't usually considered a crime (because of the can of worms that opens when you punish someone for "not doing anything"), but there are countries where people are obligated by the law to come to the aid of those in life peril. In France for example, abandoning a helpless person can earn you a prison sentence of up to five years. On the other hand, you cannot be prosecuted for a bad first aid, precisely for the reason to prompt people to help those in need no matter what, unless it would endanger their own lives as well. Of course, an exception is made for on-duty emergency workers, law enforcement, and military personnel, where failure to act is to violate your duty. It can also be your duty because of your relationship to the person: parents have a duty to rescue their minor children. Failing to act is also generally punishable if you're in some way responsible for creating the dangerous situation in the first place.
Compare Do with Him as You Will, Make It Look Like an Accident, Never Suicide, and Throw 'Em to the Wolves. Contrast Accidental Murder and Save the Villain. If the victim is murdered actively by a character and another character does not intervene, it's a case of Accomplice by Inaction or Betrayal by Inaction depending on the case. Contrast/Compare Failure-to-Save Murder where someone is held responsible for a death because they tried and failed to prevent it, Indirect Serial Killer where a murderer kills multiple people indirectly, Lethal Negligence, where a character kills people via negligence, and Bystander Syndrome when people in general don't help the victim. Is often the Face–Heel Turn for a character. Most of the time it is not a Moral Event Horizon however unless the perpetrator contributes actively enough into this to be considered indirectly culpable. This is often a favored tactic of the Technical Pacifist. Contrast Save the Jerk, where the hero might not like the person, but still goes out of their way to save them.
As a Death Trope, all spoilers will be unmarked ahead. Beware.
- Batman: In issue #633, Robin (Stephanie Brown) dies due to torture and Batman later discovers that Dr. Leslie Thompkins deliberately withheld treatment that could've saved her life but chose not to in order to teach the kids of Gotham a lesson about superheroing. After massive backlash, this was retconned into Thompkins making Batman think that Stephanie died when she was actually smuggled out of the country. (Then it was retconned even further into Batman and a few other adults in Stephanie's life being aware too, and everyone dancing around the Open Secret for complex psychological and political reasons...)
- At least one storyline saw Batman rejecting the idea of letting the Joker die this way; after the clown is stabbed by the killer Onomatopoeia as a distraction while he makes his escape, even Jim Gordon argues that letting Joker die under these circumstances isn't killing the Joker but just choosing not to save him, but Batman affirms that he can't let anyone die.
- The Batman story Knightfall has Jean-Paul Valley/Azrael do this while assuming Batman's identity. When the villain Abattoir is left dangling above a vat of molten steel, Jean-Paul is torn between fulfilling his duty as an avenging knight and killing him, or rejecting it and saving his life. Instead, he chooses neither and leaves Abattoir to eventually fall to his death — which also dooms the hostage he had hidden away. After Bruce recovers and learns about this, he realizes he can't trust Valley with the Batman identity anymore.
- Catwoman: The titular character once deliberately refused to rescue Black Mask from falling to his death from a penthouse. Since Black Mask had spent the last several issues doing horrible things to her friends and relatives and had just tried to torture her to death, this could probably be forgiven. Unfortunately it didn't work.
- Green Lantern:
- Sodam Yat hated the xenophobia of his homeworld Daxam. It reached a peak in his childhood when he befriended an alien named Tessog that had crashlanded on Daxam. Sodam's parents brainwashed Sodam and murdered Tessog. Sodam realized the truth after seeing his friend's stuffed corpse in a museum. He repaired his friend's ship vowing to leave the planet forever when the Green Lantern ring appeared and gave him another out. Years later, when the Sinestro Corps attacked Daxam, Sodam seriously considered leaving the planet to its fate.
- According to the Secret Origins of Super-Villains 80-Page Giant and his Villains Month one-shot, Sinestro's predecessor as Green Lantern was Prohl Gosgotha, who was seriously wounded after crash-landing on Korugar and loaned his power ring to Sinestro so that he could use it to fight off a Weaponer of Qward. Seeing himself as more worthy of bearing the ring, Sinestro refused to give the ring back to Gosgotha in spite of his pleas that he needed it to recover from his wounds and let him die so he would inherit the ring.
- Marshal Law: At the climax of the "Kingdom of the Blind" story arc, Law is very much capable of helping the Private Eye up rather than let him fall to his death. Watching from across the room, Law jokingly insists he "can't quite reach" as the Private Eye struggles and eventually falls.
- Spider-Man 2099: In Miguel's first encounter with the 2099 version of the Vulture, the Vulture's wings had failed and he was plummeting towards the pavement. Miguel prepared to shoot a webline to catch him...then decided not to. This was the first of many scenes wherein it was made clear that this Spider-Man is not your friendly neighborhood Spider-Man.
- Superman: In Let My People Grow!, Brainiac gets accidentally hit by his size-changing ray and is shrinking rapidly and uncontrollably. He begs Supergirl to save him, but she refuses to◊: her enlarging ray has only two shots left, which she plans to use on her cousin and the Bottle City of Kandor, and she is NOT wasting energy on him. Even Superman pleads with her, but Kara doesn't cave in◊, and lets Brainiac disappear.
- For Better or for Worse: In Michael's book Stone Season, the heroine suffers constant abuse and suffering at the hands of her cruel, controlling husband. In the climax, she goes out to search for him after he spends too long out on a ride, and finds him lying in the snow, injured. She simply turns around and heads home without him, leaving him to die.
- This is revealed to be Steele's ultimate goal near the end of Balto, where he plans on killing not just Balto and his sled team, but also everyone in Nome, all out of spite due to his hatred against the title sled dog, by deliberately sabotaging the former's journey to Nome to deliver the medicine that will save everyone from a deadly disease, and then heading off to Nome alone and making it look like it was just a tragedy so that Steele can trick everyone into gaining his trust. However, thanks to the help of the White Wolf, Balto and his team were able to successfully get the medicine to Nome in time, and as a result everyone the moment they see Balto and team alive and well immediately learn of Steele's treachery, causing them all to turn against Steele and start treating him like an outcast instead.
- In Corpse Bride, Done more or less by most of the characters both and living and dead to Lord Barkis who should know better than drink from a glass of wine the dead brought just because he couldn't resist some Evil Gloating and wanted to have the last word. Nobody could stomach him getting away with his crimes and thus nobody felt the least bit sorry when he got his.
- The Emperor's New Groove: As Kuzco and Pacha cross a rickety old bridge on their way to the palace, Pacha falls through and ends up tangled up in the ropes. Rather than help him up, Kuzco leaves him there, saying that it's better than imprisoning him in a dungeon as per his original plan. This backfires immediately when he too falls, forcing the two of them to work together to save themselves.
- Frozen: Attempted by Prince Hans when he first chooses to withhold a potentially life-saving Almost Kiss from Anna, since an act of true love would save her from freezing to death from Elsa's magic (although said act is eventually done by Anna, not for Anna) then leaving her to succumb to her frozen heart. You could argue that he also sped up the process by extinguishing the fireplace, but ultimately, it was a choice not to save, rather than to kill. His kiss probably wouldn't have saved her anyway since he didn't love her, but it's clear that the way he almost does it and then turns away is mostly to rub it in.
- In The Lion King (1994), it seems like this is how Mufasa is going to die: after luring Simba into a ravine that the hyenas are going to drive a herd of stampeding wildebeest through, it looks as though all that Scar will need to do is sit there and gloat after Mufasa gets Simba to safety but can't save himself without Scar's assistance - but Scar, prideful, treacherous and sadistic to the end, can't resist the opportunity to Kick the Dog and throw Mufasa off the cliff anyway.
- Spider-Man: Across the Spider-Verse shows that this is considered a policy among the Spider Society due to Miguel O'Hara's belief in the "Canon Event" theory in that certain events crucial to Spideys must be allowed to play out, including deaths meant to give emotional burden lest it results in said universe falling apart, meaning that certain individuals (specifically police captains such as Captain Stacy and other equivalents) are Doomed by Canon and their deaths must be allowed to play out. Miles learns that by that logic, his father's death is considered a Canon Event and thus seeks a way to avert his fate thus bringing him into conflict with Miguel.
- Toy Story 3: Rather than save the toys from being roasted by the incinerator by pressing the emergency stop button to shut off the conveyor belt, Lotso instead decides to abandon the toys even after they risked their lives to save him.
- Aquaman: The title character leaves Jesse Kane to his death, despite the pleas of his son David. Given that Jesse responded to Aquaman's offer of mercy with an attempted backstab, he is right to give up on him. Unfortunately David Kane survives the ordeal and becomes the infamous Black Manta.
- Batman Begins: Batman uses this as a loophole around his "no killing" rule to dispose of Ra's al Ghul, who's caught on an about-to-crash train. The waters are muddied even further by the fact that he had James Gordon ride the Tumbler (a tank-esque Batmobile) and take out the bridge supports ahead of the train to cause said crash, and in that all of this was ultimately caused by Ra's, including Bruce becoming Batman in the first place since he all but orchestrated the Wayne murders in this version of the story.
Batman: I won't kill you... but I don't have to save younote .
- In Falling Down, Villain Protagonist Bill's second victim was a wealthy Grumpy Old Man who he caused to have a heart attack with his Reckless Gun Usage. Rather than attempting to aid him in any way, Bill mocks him as he lays dying.
- The Fifth Element: Subverted. Immediately after Zorg gives Cornelius a diatribe about survival of the fittest and the necessity of destruction, he starts choking on a cherry pit. Cornelius takes some time to point out the irony, but ultimately thumps him on the back to save him. Zorg, who before and after this scene would show he'd kill people for the crime of getting on his bad side, chooses to allow Cornelius to live and leave unharmed for this (if still throwing him roughly to his goons to be escorted out).
- Gladiator: After Maximus disarms Commodus in the arena, Commodus immediately starts demanding one of the surrounding Praetorian Guard to give him a sword. If he hadn't recently and publicly dishonored his own royal guards, they might have.
- Johnny Belinda, although this example might be just straight-up murder. Locky's fight with Black by the edge of the cliff ends with Black slipping off the cliff, scrambling for a foothold. Locky stands and watches as Black slips off the cliff and falls to his death.
- Ju Dou: Jianshan's deeply disturbing death. It is clear that Tianbai, then a child of elementary school age, didn't mean to knock Jianshan's wheelchair into the red dye vat. But as Jianshan flails around, his dead legs dragging him down, Tianbai watches. And smiles. And laughs.
- Killer Toon: Mi-suk's mother suffers from a horrible facial disfigurement (cause unspecified) that includes among other things a missing eye, ghastly scarring, and holes in her cheek. Mi-suk, sick and tired of being a social outcast because of her mother, writes that she wishes her mother were dead. Mom finds her daughter's journal and hangs herself—and seconds after she kicks away the chair, Mi-suk walks in and finds her mother strangling to death on the rope. Instead of doing anything to help her mother, Mi-suk steps back and watches her die.
- Kiss of the Damned: Irene, the vampires' servant, comes across Maia crawling toward the house to get in from the sunlight. She ignores Maia's pleas that she help, lighting a cigarette from her burning body and watching her die. As Maia is a Serial Killer, it's hard to care though.
- Leave Her to Heaven: Ellen follows in a boat as Danny, Richard's disabled brother, goes for a swim, then sits back and puts on her sunglasses to watch as he flounders, calls out for her help, and sinks below the surface of the lake, all because Richard was paying attention to Danny, and not to her.
- In Let Me In, Owen cements his Face–Heel Turn by declining to help the policeman who's being attacked by Abby and is pleading for help, instead closing the door and letting Abby finish him off.
- My Cousin Rachel (1952): Rachel says she's going to be walking along a route that Phillip knows to be dangerously unsafe because the carpenter told him the bridge has not been finished yet. He doesn't say anything. She falls to her death.
- My Cousin Rachel (2017): Phillip suggests that Rachel go riding along a route where he himself nearly fell to his death earlier in the film. Sure enough...
- George Eastman, the protagonist of A Place in the Sun plans to kill Alice, the girl he made pregnant by arranging a boating accident because her death would free him up to be with his true love. He can't bring himself to kill her, but the boat still capsizes accidentally, and George does not try to save Alice.
- Prince of Persia: The Big Bad's goal is to do this: go back in time to when he had saved the future Sultan's life as a boy, and this time do nothing, so that the then-Prince would die and he would become the next Sultan.
- Sabretooth: Catherine callously kicks away a badly wounded survivor of the monster's attack on the cabin as the woman begs for help and then doesn't tell anyone else about seeing her, so they won't abandon the search to get the hurt woman medical attention.
- Star Trek VI: Kirk is infuriated to find he has been nominated to extend "the first olive branch" of peace to the Klingons, who can no longer afford to maintain hostilities with the Federation. Kirk has hated the Klingons outright ever since they killed his son and when Spock attempts to persuade him that it's the right thing to do he replies "Let them die."
- Reversal of Fortune: One of the possible solutions to the mystery of what happened to Sunny is that her husband failed to give her aid after an attempted suicide.
- Saw: John Kramer adamantly insists he's never killed anyone in his role as the Jigsaw Killer; he merely puts them in Death Traps, and the traps kill his victims because they failed their tests. Of course, since he knows the traps are fatal to those he puts in, that doesn't make much of a difference. Eric Matthews puts it best in Saw II:
Eric: I don't know what [the cure for cancer] is, but I know it's not killing and torturing people for your own sick fucking pleasure.
John: I've never murdered anyone in my life. The decisions are up to them.
Eric: Yeah, well, putting a gun to someone's head and forcing them to pull the trigger is still murder.
- Tormented (1960): When Vi is hanging from the broken railing of the lighthouse, begging Tom Stewart to save her, he starts to move in, and then decides to just stand idly by and watch her fall to her death. He makes a half-hearted attempt to move in once she's already plummeting.
- Tristana: When Don Lope is having a heart attack, Tristana pretends to call the doctor but never actually lifts the receiver. Then she kind of moves onto Murder By Action when she opens Don Lope's window to the bitter winter cold.
- In Count Yorga, Vampire, the Count is walking through the grounds of his castle talking to an old priest, who accuses the Count of being a vampire and killing several people (which is all true). The Count dismisses these accusations, and continues walking and talking with the priest, until they get to a section of boggy ground. The Count (being a vampire) does not fall into the quicksand, but the priest does. As the priest sinks under the bog begging for help, the Count admits to being a vampire, shies away from the cross that the priest holds up, and then watches from a distance doing nothing as the priest disappears and drowns.
- Zone 39: The narrative makes plain that by covering up the water contamination continuously in the titular Polluted Wasteland, the corrupt Commander-in-Chief Tito has knowingly sentenced a portion of the populace to death.
- If you saw a lawyer and a politician drowning, and you only had time to save one of them, would you go to lunch or read the paper?
- In Carrie Underwood's "Blown Away" a young girl gets rid of her abusive father by taking refuge in the storm cellar (and locking the door from the inside) while he’s passed out drunk and there’s a tornado headed straight for the house.
She heard those sirens screaming out.
Her daddy laid there passed out on the couch.
She locked herself in the cellar,
Listened to the screaming of the wind.
Some people called it taking shelter.
She called it sweet revenge.
- Tanya Tucker's "No Man's Land" is about a young girl being raped, growing up to be a nurse, and seeing that one of her sick patients is her rapist. She denies him medical aid while he begs for mercy and leaves him to die in prison.
Years later Barney Dawson lay in prison,
In feverish pain, that suffering shell of a man.
He was glad to see the nurse from Millard's Clinic,
Till he saw the burning eyes of No Man's Land.
- A popular Urban Legend surrounds the Phil Collins song "In The Air Tonight". The legend usually involves someone watching someone else drown and being unwilling to help along with several other variations. In actuality, the song was about Collins' divorce.
- In Eminem's "Stan", Stan refers to the above Phil Collins rumour during the third verse, relating it to his own situation: by this point, the lack of reply from his beloved hero has driven Stan to commit murder-suicide. In the sequel song, "Bad Guy", Stan's younger brother Matthew sets out to get revenge on Eminem, believing that Eminem committed this trope by way of not responding to his brother's letters.
- The narrator of "Water's Edge" by Seven Mary Three witnesses a young woman's murder and is racked with guilt for failing to intervene, though he knows the killers will likely come after him if he talks.
- Episode 2 of In Strange Woods has characters speculate that Howl let Jacob die after making his initial call to the police, only confirming that he found the boy when it was too late. In the past, Howl let his uncle and seven others die because he didn't tell anyone about the cracks in the fuel drums, even though it was his job.
- A Gentleman's Guide to Love and Murder: Monty's first murder ends up being this, as in his attempts to get the D'Ysquith family to recognize him and his disowned mother, he and Reverend Lord Ezekial D'Ysquith end up at the top of a bell tower on a gusty day. When Ezekiel, who has refused help Monty, loses his balance on the tower, Monty decides to let him fall as revenge for his mother, putting him one-step closer to inheriting the family estate.
- In The Little Foxes, Horace decides to cut his evil wife Regina out of his will, and tells her so. Shortly thereafter he feels a heart attack coming on and asks Regina to fetch his pills. She does nothing, instead watching as he collapses on the staircase. He dies a few hours later without changing his will.
- Little Shop of Horrors: Seymour tries to shoot Orin the Depraved Dentist, but can't bring himself to. Moments later, Orin gets himself high inside a mask full of nitrous oxide (laughing gas) but finds he can't get it off and begs Seymour to help him get it off (while he laughs maniacally.) Seymour just stands by and Orin suffocates.
Seymour: What we have here is an ethical dilemma. / 'Less I help him get the mask removed, he doesn't have a prayer. / True, the gun was never fired, / But the way events transpired, / I can finish him with simple laissez-faire!
- Apollo Justice: Ace Attorney: One of these is planned, but fortunately never actually comes into being as Apollo gets involved first. Wocky Kitaki was shot some time ago, and his surgeon Pal Meraktis claimed to have removed the bullet. But as Pal and his assistant Alita knew, Pal didn't have the expertise to remove the bullet because it was too close to Wocky's heart. Pal didn't tell the Kitakis about this because he thought they'd go to another doctor if they realized he couldn't save their son's life, and Alita took advantage of the situation to get engaged to Wocky, as his health was very fragile because of the bullet still near his heart and he'd probably die shortly after they got married, leaving Alita his inheritance. However, Pal tried to kill Alita thinking she was going to expose the deception to Wocky, and Alita ended up killing him in self-defense, with Wocky's condition coming out during the trial.
- It's revealed late into Your Turn to Die that Keiji Shinogi refused to prevent his superior officer Megumi Sasahara from being ripped apart by chains.
- In the ASDF Movie deleted scenes, Superguy refuses to save a man hanging from a cliff, leaving the man to fall to his death.
- Gunnerkrigg Court: Deigo to Jeanne. The guilt of him indirectly killing the woman he loved ate him for the rest of his life. It's double-subverted; he was envious of her lover and helped a Court conspiracy that involved killing them both. Except he desperately wanted to renege on the second part of the plan and save Jeanne from a slow death by starvation followed by a tortured existence as a bloodthirsty wraith, but he was too afraid of the other Court members to defy them.
- Acheron says this of the elves in Inverloch when—after it becomes clearer and clearer that elven society is isolationist, arrogant, selfish, and hypocritical—he learns that his father was killed by an elf for the offense of... being mad that the elves had reneged on their word to protect the da'kor. Lei'ella, an exiled elf who's herself pretty disgusted with them, delivers a What the Hell, Hero? for his willingness to let the entire race die (including the girl he undertook the quest for in the first place) just because the ones in charge are terrible. In the end, the elves are saved but are forced to recognize and reform their ways.
- The Order of the Stick: When the Faux Affably Evil Thieves Guild leader Bozzok is being beaten to death in front of Grubwiggler, one of the people he's extorting for protection money, he gets a very clear explanation of why no help will be forthcoming:
Grubwiggler: I'm sick of your banal little guild's petty intrigues interfering in my magical research. All I want is to be left alone, and I suspect your eventual successor will be more willing to accommodate that desire. ...Farewell, Bozzok. You were never as clever as you thought you were. [Teleports away, leaving Bozzok behind]
- Dragon Ball Z Abridged: Following the scene where Krillin has mortally wounded Vegeta (as Vegeta requested), Dende is understandably unwilling to heal him on account of his partaking in the Namekian genocide. He reluctantly does so when Piccolo points out how screwed they are without Vegeta's assistance.
- In Dream's "Minecraft Speedrunner VS 3 Hunters Finale Rematch", the Hunters are in the Nether fortress and Dream is chasing Sapnap, when all of a sudden Sapnap gets stuck fighting two wither skeletons while cornered. Dream just watches this happen as Sapnap begs him for help.
- In the Dream SMP, during the Red Banquet, Quackity didn't save Foolish from being executed by the Eggpire because he wanted to recruit Foolish to join Las Nevadas and "teach" him to embrace violence again, though this isn't revealed until after the incident. Foolish calls him out on this when he learns about it.
Foolish: You threw away my life for some kind of fucking sales pitch?!
- In Sword Art Online Abridged, Kirito almost does this when he comes home to find Suguha choking on a muffin, but to his own disappointment has undergone too much Character Development to go through with it.
Kirito: (thinking) This is it... this is the icing on my cake! A lifetime of physical and psychological abuse, brought to a swift and satisfying end! All I have to do... is nothing! I mean, this is just Darwinism at work! As long as I don't hand her this lifesaving juice that I am currently handing her NOOOOOOOOO!!