Who Murdered the Asshole? is a popular plot in murder mysteries because it gives the maximum number of suspects with a reason to want the victim dead. Some works take it a step further and have not only multiple characters who wanted the victim dead, but who actually attempted it.
This will leave the detectives with a lot of contradictory evidence, which will not make sense until they realize that there were multiple attempts on the life of the victim. And once they figure that out, they then need to work out who was responsible for each of them and which (if any) actually succeeded.
In Real Life, those who tried to kill the victim and failed would still be guilty of attempted murder. Sometimes a work will acknowledge this, and sometimes not.
A subtrope of Gambit Pile Up. Compare Two Dun It and Everybody Did It, where multiple people succeed at murder. Can overlap with Two Rights Make a Wrong if multiple murder attempts accidentally cancel each other out. See also Colliding Criminal Conspiracies.
- One case from Case Closed plays out like this when an actor is found dead at the theater where he worked. The three other actors each confess to killing him by smashing a vase over his head, with forensics finding skin particles from the victim on each of the three vases. However, the autopsy revealed the head wounds were not serious enough to kill him. His real cause of death was heart failure due to his wife swapping his heart medication with stomach medication.
- Death, Lies, and Treachery: In the third issue, three people want Orko the Hutt dead.
- Orko's son-in-law Gorga hires Boba Fett to kill Orko. After he finds out his wife is pregnant, he changes his mind and tries to call Boba off, but he can't reach him. Ironically, Boba betrays Gorga and offers to spare Orko's life in exchange for the money Gorga offered, plus 100,000 credits.
- Orko's mistreated servant Hisroot tries to stab him in the back, and then poison his sandwich but is interrupted both times.
- Ry-Kooda attacks Orko's mansion to avenge the death of his brother and rips Orko to pieces.
- In the EC Comics story "Three for the Money", a man is found with a bullet hole in his head and a thrown knife in his back, as two assailants had simultaneously tried to kill him (one from the front and one from behind). The detective points out that whichever one of them DID kill him, the other is still guilty of attempted murder. As it turns out, the victim was already dead, poisoned by his wife.
- Played for Laughs in the Infinity spin-off Fate T. Harlaown and the Case of the Murderous Murder. Every single suspect thinks that they succeeded in killing the governor, but he actually choked to death on a nut.
- In Gosford Park, the murder victim was stabbed while sitting in a dark room alone. He had already been killed by poison.
- In trope-laden sex comedy The Naked Detective, three different harpies are trying to kill old man Harthcourt Higglesbotham III for his inheritance (and because he's a cantankerous old bastard who's been making their lives miserable knowing they'll do anything for the estate). Fourth wife Roxanne was trying to poison him with rat poison, nurse Annie was trying to overdose him on his vitamin K medication, and daughter-in-law Irene was trying to shoot him (badly). Rat poison is basically blood thinner, while vitamin K is a coagulant—they cancelled each other out. Of course, it still sent his blood haywire and caused seizures, but the attempted shootings were raising his adrenaline levels, allowing him to ride them out. Actual killer (by accident?): his nebbish son, whose OCD bug-spraying inadvertently poisoned his antacid pills.
- In Once Upon a Crime, none of the protagonists had any reason to kill the victim to begin with, but a series of ill-advised actions and hijinks dig them so deep that they have to resort to further hijinks to cover themselves, including trying to dispose of the body and inventing fake alibis for each other. They also believe that the local police will not believe them and will pin the crime on them just for being foreigners. Once the real murderers have been caught, the actually very sensible police call them out on that last bit.
- In The Phantom of Crestwood, Vayne was actually attempting to murder Jenny Wren when the real killer beat him to it.
- In The Trouble with Harry, multiple characters think they might have killed Harry, which results in his body being moved multiple times as they try to hide their possible guilt. In this case, none of them actually set out to murder him, but each one believes they may be guilty of at least manslaughter. It turns out none of them actually killed Harry.
- In The Big Over Easy, nearly every suspect in the book actually tried to kill Humpty Dumpty, but didn't succeed. His ex-wife thought she shot him, but actually killed his friend, his lover poisoned his coffee which he didn't drink, Lord Spongg wired his car with a bomb but Humpty didn't drive it it, and Solomon Grundy hired a hit man who shot Humpty when he was already dying. The real killer? Humpty's crazy doctor who used him to incubate a monster, killing Humpty (who is literally a large egg) when it hatched.
- The children's book series adaptation of Clue usually uses some version of this for the final case in each book. The host, Mr. Boddy, finally does something to incite his guests beyond mooching, larceny and infighting into actually trying to kill him out of cupidity or fear of exposure, they all either off each other trying or simply get in each other's way, while their host typically has a ridiculous run of luck avoiding murder attempts until one finally gets him. (In the next book, it's revealed why nobody actually died and why the host chose to forgive everybody everything. Although he does keep hiring you to come back the next time he's inviting the usual suspects over.)
- In The Illuminatus! Trilogy, five assassins were actually gunning for JFK, although only one succeeded, and one other (Oswald) got caught.
- In Lauren Groff's The Monsters of Templeton, the death of Marmaduke Temple is something of a historical mystery. A flashback reveals that three different men, all with distinct grudges against him, tried to kill him simultaneously. But two of them backed off so the third could do the deed. Temple's wife also considers herself responsible—because she let him leave the house that night, even though she foresaw his murder.
- In "Soft Pawn" by William Hartston, thirteen grandmasters kill an expy of Bobby Fischer. Except this is a Sherlock Holmes parody, and all the chess-related herrings were red. It was Keffeagh Bacdabb. Actually McNab...but he had the flu. Yes, it's that kind of silly.
- An Invoked Trope in The Twisted Thing, by Mickey Spillane. After the first murder attempt fails (trying to induce a heart attack in the victim), the killer just puts a hatchet into his head, knowing that his death will lead to a confusion of crimes and suspects as his Big, Screwed-Up Family scrabble for the victim's fortune.
- 'Allo 'Allo!: The Resistance, Colonel von Strohm and Herr Flick all independently try to assassinate General von Klinkerhoffern. Their attempts get in each others' ways so that they all fail.
- The Coroner: In "That's the Way to Do It", the Victim of the Week is already dying as a result of having had her food spiked with shellfish to trigger a fatal allergic reaction. The second killer discovers her and beats her death with a champagne bottle. Both would-be murderers end up going to prison.
- CSI: A extreme example occurs in "Ending Happy". The CSIs are investigating the Rasputinian Death of boxer Lorenzo 'Happy' Gonzales, and discover a bizarre chain of events where the multiple murder attempts ended up interfering with each other. The drugged-up ex-boxer passes out on his favorite prostitute's bed, and is injected with snake venom by her and an accomplice. His boss's wife is fed shrimp by his boss, in order to trigger Happy's allergy when they hook up, causing his throat to swell. He's then shot through the throat with a crossbow by one of the people who injected him with snake venom, allowing him to breathe again. He figures out what the prostitute did and goes back to her room angry, and she hits him with a crowbar. Then he staggers off to rest on a chair (that he had fixed badly) by the brothel's swimming pool, and leans over to pick up a cigarette. The chair collapses under his weight and drops him into the pool, wherein he finally drowns, too weak from the rest of the injuries. And yet all of the other accused people walk away free, with Nick even snarking that a good enough Amoral Attorney will probably put all of the blame on the chair.
- In Damages, Tom Shayes turns out to have escaped torture and attempted murder by gangsters, but then to have been killed by another person after he arrived home.
- Death in Paradise: In "She Was Murdered Twice", the body of a woman is found shot in her bed at a company retreat. After Humphrey talks to the people on the retreat and gathers evidence, he finds a suspect who confesses to having shot the victim. After putting him in jail to await trial, the coroner's report comes in and says that the victim was smothered to death before she was shot, and Humphrey has to go through the suspects again to find the original killer. In the end, it's a subversion. There was only one killer, who murdered the victim in the heat of the moment, and quickly realized that he would soon become the prime suspect and be arrested. With nothing to lose, he tries to get sent to prison for attempted murder and receive a significantly shorter sentence. He shoots the corpse, and when the police start to close in, he "confesses" to having murdered the victim by shooting her. Then he just waits in his cell for the coroner to send the police on a wild goose chase. Humphrey ends up having to catch the same killer twice for the same murder.
- In one episode of Foyle's War, the victim of the week is left incapacitated but not dead by a blow to the head from one intended killer, then dragged off and drowned by a second, unrelated assailant.
- The Glades: In "Marriage Is Murder", the Victim of the Week is an Amoral Attorney who has his drink spiked with antifreeze. However, someone else stabs him before the poison can take effect.
- Murder, She Wrote: In "The Error of her Ways", the first Victim of the Week was shot by his wife who then fainted. The murderer - having witnessed the shooting - came in to steal a Briefcase Full of Money. Realising the husband was still alive, the killer smothered him with a Vorpal Pillow. When the wife awoke, she discovered her husband dead and - assuming she had killed him - attempted to cover up the crime by making it look like a robbery gone wrong. The real murderer later killed the wife to make it look like she had committed suicide out of guilt.
- New Tricks: In "Life Expectancy", the team recover what they think is the weapon used in a fatal bludgeoning: a marble phrenology bust. After investigating, they finally get a suspect to confess that she struck down the victim with the bust. However, after this, forensics reveals that the fatal blow did not come from the bust, and the team realise that someone else had come along and finished the job.
- Ripping Yarns: Played for Laughs in "Murder at Moorstones Manor" where four different characters confess to the murder, complete with Motive Rant, before they end up killing each other. Each is utterly convinced they are the murderer, and it leaves the one surviving character thoroughly confused.
- Rizzoli & Isles: In "Sister Sister" the Victim of the Week is subject to two separate plans to poison her. The second poisoner was aware of the first attempt and deliberately timed theirs in hope that it would be masked by the first attempt.
- In the boardgame Kill Dr. Lucky, all the players are attempting to kill the good Doctor, and the winner is the first one to succeed.
- The plot of the second expansion of The Outer Worlds is kicked off when you're hired to investigate the murder of a famous actress who was found beaten, shot, and poisoned with multiple toxic substances. You soon discover that all her injuries were caused by the independent schemes of different people; she was (non-lethally) poisoned by a rival to make her miss an important event, accidentally overdosed by a drug dealer who gave her too high a dosage, fatally beaten over the head with a bottle (needlessly; she would've probably died from the double-poisoning, not that the killer knew) by a third party whose crimes she was threatening to expose, and finally had her corpse shot up by the same third party to conceal the true cause of death.
- In the comedy Hidden Meanings, a dead body is found hidden in a cupboard. Over the course of the play, pretty much every member of the cast admits, with varying amounts of guilt and/or pride, to having done the deed — including the victim, who is discovered at the end of the play to be carrying a suicide note.
- In one case of Danganronpa: Trigger Happy Havoc both Yasuhiro Hagakure and Genocide Jack believe they killed Sakura Ogami by hitting her over the head with a bottle, but things aren't quite what they seem. Sakura actually killed herself.
- And in Super Danganronpa Another 2, Nikei Yomiuri, Yuki Maeda, and Sora are all believed to be the culprits for the murder of Shinji Kasai; Nikei knocked himself and Yuki out to manipulate Yuki into slashing Shinji's throat with a glass shard. Then Sora came along and slashed Shinji's throat again, but using the unconscious Nikei's hand to try and invoke Cartesian Karma. They also discover that things aren't as they seem. Shinji managed to survive both these attempts and committed suicide to prevent anyone from becoming the Blackened; not that it helps Nikei in the end.
- Danganronpa Re:Birth: Zen Katagiri doesn't go down effortlessly. It starts with Kazuomi Samejima pushing him down the stairs, breaking his leg. Then Kazumi Izumo strangles him. Then Narumi Osone cooks him a poisonous meal. It culminates in Marin Mizuta accidentally killing him by suffocating him while trying to attempt CPR. To add insult to injury, Mikoto Itsuki posthumously decapitates his corpse.
- Played for Laughs in the Daria episode "Murder, She Snored", in which Daria dreams that Kevin is murdered and she's the prime suspect. As it turns out, everybody but her did it, all unaware of each other's plots and thinking they were the sole murderers. Even though they all fess up when Daria starts pointing fingers, Daria gets convicted anyway and is about to be executed before she wakes up.
- The Smiling Friends episode "Who Violently Murdered Simon S. Salty?" focuses on Pim and Charlie trying to figure out who violently murdered fast food mascot Simon S. Salty, finding each of the other mascots all had a motive to want him dead. Eventually, they manage to get a security tape of the murder scene, forwarding and rewinding the tape to show every single suspect trying to kill Salty in his sleep. Then they rewind the tape to the very beginning and see that Salty died of a heart attack right before going to bed, due to spending years eating nothing but unhealthy burgers.
Pim: So I guess that means they're all innocent. Salty technically died from a heart attack.
Charlie: I mean all these characters are definitely psychopaths, but I guess none of them killed him.