Meet Bob. He's a member of the True Companions, he has personality traits, likes and dislikes, strengths and weaknesses, and maybe even a romantic interest. After a few adventures with his friends, it's time to learn a bit about his past. As it turns out, the horrible secret he's been concealing all this time is... he once killed a man. The other characters are horribly shocked. While some will be able to look past his crime, a few may never forgive him and their relationship will become strained. To the viewer, Bob is obviously deeply emotional by what he's done; he probably still has nightmares about the murder, and he prays every day he could take it back. Bob continues to be the same character he always has been, but the audience henceforth views him in a newfound light. This, dear troper, is Murder as a Sympathetic Backstory.
Murder is serious business. Taking the life of a sentient being is a deeply ingrained taboo in the human psyche. In stories that do not frequently involve death (action, horror, thriller, etc.) the intentional extermination of another human being is a big fucking deal. Of all the troubled backstories Bob can have (dead/abusive/absent parents, Cynicism Catalyst, rape, doomed hometown, etc.) revealing him to be a murderer simultaneously makes him a killer and the woobie. The revelation may make his friends question just what makes a 'bad guy'.
If Bob's reveal of his backstory comes with a flashback, expect it to take almost the entire episode. It will likely go over Bob's every single option in the situation. You will watch as the victim pleads for his life, or, alternately, goads Bob. The eventual death will definitely be utterly heartbreaking. If the flashback continues after the murder, expect Bob to express "My God, what have I done!" or at least stare down at his hands with horror. Extra angst and woobie points if he has to kill a parent/sibling/spouse/child/old friend/dog.
90% of the time, Bob was forced to commit the murder. He might have done it in self-defence, to save someone he loves, a Bad Guy might have put a gun to his head and ordered Bob to kill Alice, Alice might have begged Bob for death, Bob might have just been following orders, the list goes on. If the character wasn't forced into the murder by a third party, expect the victim to have been an Asshole Victim (see also Good Victims, Bad Victims).
Take note that this trope only works with sane, intentional murder. The murder was not an accident; Bob didn't unintentionally shove grandma down the stairs. Do NOT include manslaughter/accident examples. The reason murder can be and has been a genuinely sympathetic backstory is because Bob simply had no other choice and had to kill Alice, all the while being horrifyingly aware and in control of his actions.
In Fandom, this is frequently called "manpain", because it disproportionately affects male characters and relies on their guilt being more significant than the suffering of the person who is actually dead. Because people who are dead can't suffer.
Expect him to either loathe the thought of killing someone else or be terrified by the fact he discovered he enjoys killing. If he's not tormented by the memory in some form, the backstory is not sympathetic, and therefore not this trope.
Related tropes: Freudian Excuse, These Hands Have Killed, My God, What Have I Done?, A Death in the Limelight, etc. The people most commonly seen with such backstories: Sympathetic Murderer, Shell-Shocked Veteran, Hitman with a Heart, etc.
As this is a Death Trope, beware unmarked spoilers.
- Guts, from Berserk, had to kill two major people in his pre-Hawks backstory apart from those he killed in battle as a child mercenary. The first was Donovan, a pederast soldier in his adoptive father Gambino's band, who Guts killed in revenge for having raped him. The other was Gambino himself, who Guts had to kill in self-defense after Gambino lost his leg, got drunk one night and tried to murder him because he blamed the poor kid for the death of his lover from the plague. The latter killing affected him quite more strongly than the former, though he still has the aversion to being touched which came from Donovan's attack on him.
- Suzaku from Code Geass killed his father in order to force his nation, Japan, into surrendering against Britannia in hopes of preventing more deaths. He's been secretly suicidal ever since.
- Gravitation: Yuki killed someone but it was in self-defense, as they were trying to rape him. It ruined their life, so you will probably feel pretty sorry for them.
- In Fullmetal Alchemist, several military characters were deeply affected by their part in the Ishvalan genocide, but particularly Colonel Roy Mustang.
- A Cruel God Reigns: Jeremy. After learning about all of the sexual and physical abuse he suffered for months, you really can't blame him for killing his step-father. Ian, Jeremy's step-brother, struggles to accept Jeremy's claim to this trope for the second half of the series.
- In Attack on Titan, several chapters are dedicated to showing just how seriously messed up Reiner, Bertolt, and Annie are as a direct result of their crimes. Beyond the simple evidence of their extreme guilt and emotional trauma, the eventual reveal of their motivations makes them even more sympathetic to both the audience and the other characters. Child Soldiers from the nation of Marley, they were quite literally raised from birth as weapons and told their mission was to save humanity from "devils" living behind the Walls. Families were promised improved treatment as "Honorary Marleyans" in exchange for volunteering their children, with Reiner's mother in particular shown to be a fanatic. Enduring nearly a decade of brutal training and indoctrination, they were sent on their mission with the threat of being replaced and their families "purged" if they failed. And the worst part about it? It turns out their superiors had been lying to them about everything from the beginning.
- Eren and Mikasa killed three men when they were children, to save their own lives. While most accept it was self-defense, it's later used in an effort to discredit them.
- In Samurai Champloo, Jin killed his master, forcing him to run from his dojo.
- Sword Art Online has Shino Asada, AKA Sinon, a player from Gun Gale Online. As it turns out she plays this game as a way to cope with the fact that she accidentally killed a criminal with his own gun when they fought for it. This happened when she was barely eleven years old, which left her severely traumatized.
- The backstory for Storm has her killing a man who tried to rape her. And this is why she tries not to kill the rest of the time.
- There are a few other mutants whose power manifestation moments in their backstory resulted in someone dying.
- Also among the X-Men, Gambit was once "hired" by Mr. Sinister to assemble a hit squad and lead them into the home of the Morlocks, a society of underground mutant refugees. Though he didn't personally kill anyone (in fact, he saved a few of the Marauders' intended victims!), the reactions of the X-Men when learning about this was virtually identical. His good name still hasn't fully recovered, in part because he can't seem to stop switching sides.
- Tales of the Undiscovered Swords: Sasanoyuki turns out to have experienced extreme torment and self-hatred for being an Absurdly Sharp Blade that took and is meant to take countless lives, so much so that he decided to suppress his feelings and become a cold, ruthless killer in order to accept his intended purpose as a sword. His kiwame training re-triggers all this, leading him to attempt suicide at one point.
- RWBY: Scars: Blake used to be a member of the White Fang with a strong disdain towards humans. Before even having hit eighteen, she had killed several humans, both in self-defense and in cold blood. Blake has since turned her back on the White Fang and is trying to become a huntress to help others.
- In the Jodie Foster film The Little Girl Who Lives Down the Lane, protagonist Rynn hides the secret that she poisoned her abusive mother. The details on just how she did this turn out to be significant for what happens in the rest of the movie, too.
- Assassin's Creed (2016): We're introduced to protagonist Callum Lynch as a death row inmate awaiting his execution in a Texas prison. After his execution is faked and he wakes up in Abstergo Industries, we learn that his victim was a pimp.
- The backstory of the protagonist of The Shack is that as a teenager, he poisoned his abusive father. In the present day, it seems that no one knows about it but him, but it has impacted him throughout his whole life.
- In The Amazing Maurice and His Educated Rodents, we learn that Maurice once ate a talking rat. However, he was only a dumb animal at the time, and had no way of knowing until he gained his intelligence from said meal. The guilt is shown to be why he's so careful about what he eats.
- In Twilight, Edward Cullen confesses to murdering a whole bunch of people shortly after he was turned, while in the grip of The Thirst: Being a Vegetarian Vampire in this setting takes enormous self-control, and living in constant fear of that self-control slipping on top of the guilt when it does happen is a large part of why Edward is so screwed up. The rest of the Cullen family, except Carlisle, have all experienced at least one lapse themselves.
- Quillon, the protagonist in Terminal World by Alastair Reynolds, murdered his angel cohorts in his backstory. It was cold-blooded, but done in revenge because they murdered his love interest first, covered it up, and were planning on murdering him as well.
- Part of Kalix's backstory in Lonely Werewolf Girl is that she killed her father. It's part of the reason she is so lonely.
- Rebecca definitely fits, and is in fact one of the most interesting examples of this trope. The reader discovers the title character was in fact a horrible person, whom Maxim killed. It was definitely murder, and the reader is absolutely meant to sympathize with Maxim (although the revelation still has negative consequences for his relationship with his new wife).
- Adding to the complexity is the heavy implication that Rebecca deliberately goaded Maxim into killing her by taunting him with the suggestion that she was pregnant with another man's child (it's later revealed that Rebecca was sterile), because she knew she was dying slowly of cancer and wanted a quick, painless end.
- Both Eve and Roarke in the In Death series turn out to have murder in their backstories. As a child, Eve stabbed her father to death in self-defense when he raped and beat her. Roarke, meanwhile, turns out in Vengeance In Death to have gone on a Roaring Rampage of Revenge and killed several men involved in the rape, torture, and death of Summerset's daughter Marlena.
- Played with in My Godawful Life where Euphemia suggests that she murdered her father (who had sexually abused her for years) and every member of the paedophile ring he pimped her out to. After taunting the reader with her knowledge of how easy it is to sway the audience's sympathies, she then refuses to reveal whether it's true or simply made up as a form of self-therapy.
- We find out fairly early on that Harry Dresden of The Dresden Files killed his mentor, Justin, and it was clearly self-defense (even if it takes thirteen books to find out the finer details, if you're killed when attempting to psychically enslave your sixteen-year-old foster son/apprentice and trying to kill him when he resists, it can safely be put under justifiable homicide). Unfortunately, Harry used magic, and using Life Energy to kill for any reason causes addictive Black Magic. The Wardens do not see it as sympathetic, which is further complicated by the fact that in this setting, they're usually right.
- In Brightly Burning, Lavan Chitward's power of Firestarting awakens traumatically when a gang of bullies tie him up and whip him. The people investigating this incident are quite distrustful of Lan because of his actions, and a whole lot of psychological and legal problems are only avoided because 1) he was clearly acting in self-defense, ignorance of his powers, and under extreme emotional duress while committing the manslaughter (as the book debates in detail) and 2) Lan has been Chosen by Companion, one of the guardian spirits of their country, whose very presence provides incontrovertible proof of the Chosen's Incorruptible Pure Pureness and who works very hard to ensure that nothing of the kind will happen again.
Lan: I still feel guilty about [the crime], though.
Tuck: Well, you'd be a pretty poor excuse for a human being if you didn't!
- The Ascendant Kingdoms Saga: Blaine McFadden at one point muses that most of the convicted murderers at the Penal Colony of Velant are either innocent, or folks who killed somebody who had it coming and aren't likely to be repeat offenders, since the most heinous criminals were generally executed instead of transported. This includes Blaine himself, who ran his father through for raping Blaine's sister. The exception is Kestel Falke, who is a Professional Killer, but she claims that the majority of her targets were abusive or adulterous husbands.
- Jill Kismet shot her pimp dead with his own gun in self-defense after he beat her black and blue one too many times. She was never investigated for the homicide, as her hunter mentor Mikhail Tolstoi found her and took her in shortly thereafter and evidently shielded her from the police.
- From The Stormlight Archive:
- At the end of The Wayof Kings, we learn that Shallan killed her father. Wordsof Radiance expands upon this by showing that after her mother's death, Shallan's father became abusive to her brothers, the family was in deep debt and in danger of falling apart, with the eldest leaving really early on and eventually being disowned, all of which culminates in it showing Shallan killing her father in defense of one of her brothers and his girlfriend. And then Shallan remembers that the whole reason that her father went off the deep end in the first place is because she also killed her mother in self-defense and her father covered it up.
- In the Stargate SG-1 episode "Collateral Damage", Cameron Mitchell recalls a mission during which he bombed what he believed to be enemy targets only to learn that they were innocent refugees.
- Terra Nova:
- Commander Taylor killed his commanding officer when he arrived in the alternate past earth to relieve him of command of the Terra Nova colony shortly after he learned the truth about the project—that those behind Terra Nova were trying to find out how to make the portal go both ways so they can exploit the resources on the Terra Nova side. Taylor objected, the general pulled his gun, and Taylor fired first.
- This may have been set up as a background for Tim Curran in (never-materialized) following seasons. In the first season, he is sentenced to exile for a murder over gambling debts; later, he is recruited by Taylor to spy on the opposing faction, and rescues a hostage. Taylor's own experience leads him to welcome Curran back to Terra Nova for a second chance.
- Once Upon a Time tries to portray the Evil Queen this way when she has to sacrifice that which she loves most for her Curse. She tried her beloved and prized stallion; that didn't work. It turned out to be her father, after whom she named the boy she adopted.
- Lord John Roxton's past in Sir Arthur Conan Doyle's The Lost World. He and his brother William joined an expedition to Kenya because Roxton and his father thought it would make more of a man out of William. The older Roxton brother was attacked by an ape and John tried to save him. It went wrong... and left him a broken man. Especially when it all comes back to haunt him in form of the expedition leader also appearing on the Plateau at one point.
- Ray Carling in Life on Mars and Ashes to Ashes (2008). With the ultimate reveal that the world of the series is an afterlife for deceased police officers, it turns out that he committed suicide out of guilt - unable to follow in his father's and grandfather's footsteps by joining the army, his family disowned him and his sorrow and frustration led him to beat a man to death outside a pub, which Ray's superiors covered up in order to protect him.
- In the third season of Leverage, it's revealed that Eliot was once a hitman who worked for the Big Bad. May be considered a subversion, in that it's not all that shocking a development, given his current line of work- although he does say that the worst thing ever did occurred when he worked for said Big Bad. It's been strongly implied that it involved murdering children.
- NCIS: Gibbs' wife and daughter were murdered by a Mexican drug dealer. When the federales weren't going to help find the killer, Gibbs followed him to Mexico and got his revenge.
- An elderly Marine and Medal of Honor recipient for his service in Iwo Jima during WW2 starts an episode confessing to Gibbs for murdering his fellow corporal. Out of respect and sympathy for a decorated veteran whose mind is clearly slipping in his old age, he does enough digging to uncover the truth: During Iwo Jima, the confessing Marine, Ernest Jorst, struck the other corporal in the head to silence him so his crying from land mine injuries wouldn't give away his patrol's position to approaching Japanese soldiers. Jorst was suffering from delayed stress disorder triggered by the recent death of his wife, who had previously been his friend's high school sweetheart, making Jorst question whether he'd killed him to keep him quiet or steal his girlfriend; after being cleared, Jorst remembered that his friend had given his blessing to the engagement, alleviating at least some of his guilt.
- In South Pacific, "the Frenchman," Emile de Becque, had to flee his homeland because he killed a man. But it's okay because the victim was a bully!
- Actually, that was manslaughter. It was in a Bar Brawl and he didn't intend to murder him.
- What wasn't okay was him having had children with a South Pacific Islander, because interracial marriage seemed worse to his Love Interest than murder.
- In Show Boat, Parthy tries (and fails) to stop Gaylord Ravenal from marrying her daughter because he once killed a man.
- In Silent Hill 2, James eventually discovers that he smothered his wife to death either to end her suffering, to get her out of his life or both, this presumably being the reason the Town is tormenting him. Depending on the ending you get, this could serve to make him more sympathetic or to make him look like a monster though.
- In Metal Gear Solid, Snake is tormented by his murder of Big Boss and especially Gray Fox. Significantly, it's when he describes to Naomi how his murder of Gray Fox was done with professionalism and with no hatred, and that they loved beating each other to death ("like a sport"), that Naomi begins to realise that Snake is a Good Is Not Nice and a Type III Anti-Hero.
- In Amnesia: The Dark Descent, Daniel is manipulated by Alexander into sacrificing what he thought were criminals. He is devastated after he was forced to kill a little girl, and nearly loses his sanity. He vows revenge on Alexander for that. Amongst the flashbacks in-game involve the cries of the lives he took (children's voices were amongst them).
- In Fallout: New Vegas Craig Boone and many other members of the NCR military were traumatized by the incident at Bitter Springs, in which they were ordered to fire upon fleeing civilians due to a miscommunication.
- He also had to kill his wife when she was captured by legion slavers to save her (and their unborn child) from a Fate Worse than Death.
- One of Suikoden V's biggest Tear Jerkers occurs when Lyon reveals she was a former member of Nether Gate, an assassin's guild in service to Falena's royal family. They took her in while she was still a child an trained her. She was eventually rescued by the prince's father, Ferid, who gave her the name Lyon, and she goes on to become the prince's bodyguard as her way of repaying Ferid's kindness.
- In Last Scenario, it's eventually revealed that amnesiac party member Ethan killed a soldier when he was fourteen in defense of his brother. What makes this especially traumatic is that the soldier in question was the son of one member of the party and the best friend of another, so Ethan got a huge helping of guilt along with his nasty childhood memories once he remembered.
- Fear Effect 2: Retro Helix reveals that Glas had a brother named Drew. Drew shot him in the back, and would have murdered him for money and perceived betrayal that caused the loss of his right arm. A struggle broke out, Glas grabbed the gun and fired, killing his brother. There are hints that Jin AKA Yim Lau Wong (King of Hell) manipulated Drew into doing this. Unfortunately, one thing that ruins the scene is that Glas is unable to punch people out. He could have simply punched Drew out, which wouldn't have been too hard, considering the guy was unarmed and had only one arm!
- In Mass Effect 3 you can meet a Shell-Shocked Veteran Asari named Aeian T'Goni, who after killing a large group of indoctrinated to reach a radio to call for help, had to kill the girl she was hiding with to avoid discovery, because she had broken her leg and couldn't stop whimpering. Worse, it's strongly implied the girl was actually your pilot Joker's sister.
- Rule of Rose is an odd example. The good ending is achieved not by directly killing Gregory, but indirectly- by giving him the gun he needs to kill himself. Because Gregory is actively trying to murder the protagonist at this point, many players naturally did not realize doing this was an option (though, if one has paid really close attention to Gregory's characterization, horrific mental health, and the game's general philosophy, his actions kind of make sense). And it only works if you do it during one of the fight's brief intervals where Gregory realizes what he's doing, stops fighting, and prays for forgiveness. The game wants you to be empathic, not suicidal.
- In God of War, Kratos' regret for killing his family in a fit of bloodlust is one of the few sympathetic aspects of his personality...not that it stops him from murdering everyone else afterwards. Literally, everyone.
- In Drowtales, this happens to Ariel Val'Sarghress. She is ordered to kill Mir'kin Vel'Vloz'ress, and while she initially is reluctant after she's told her other option is killing her also-a-kid cousin, one of her few allies, she reluctantly does the deed and sports a Thousand-Yard Stare in the immediate aftermath. Not long after she accidentally kills Yafein Val'Sullisin'rune's slave Maya in a fit of rage after he pushed her Berserk Button while she's in the middle of a Heroic BSoD resulting from the disappearance of her best friend. It's clearly hinted that the resulting My God, What Have I Done? moment resulted in PTSD. It's particularly disturbing when you remember that due to her species' slow aging process, she was physically still a small child at the time.
- In El Goonish Shive, Susan had to kill an Aberration back when she was in her freshman year of high school. It's made worse because the Immortals who asked her to do it basically tricked her into doing so, and made her think there was no one else who could and no alternative, both of which were not true. When another Immortal hears this story he's incredibly pissed and swears to help them to try and make up for it.'
- Vriska from Homestuck, takes this to an extreme. In order to keep her lusus from eating her or dying from starvation leaving her a defenseless orphan, she had to kill several thousands of trolls. A more specific example includes her murder of Aradia, which she was manipulated into by the omniscient Doc Scratch. The trope also applies to Terezi, who assisted Vriska, although she did attempt to steer the violence towards trolls she viewed as immoral. The trope is played with when Caliborn claims to be torn up about the tragic loss of his sister to murder as part of the reason he is a "tortured artist" but the fact he's never once showed regret for killing Calliope in the past and never shows it again makes it hard for anyone, in universe or out, to offer genuine sympathy.