Hangman is a serial killer who murders police officers on every holiday of the year, leaving behind a version of the children's word game "Hangman" (with key letters missing) spelled with letters in blood on each new victim. During the events of Batman: The Long Halloween (to which Dark Victory is a sequel), Batman captured and imprisoned Alberto Falcone, the serial killer known as Holiday who murdered members of the Falcone crime family on holidays (although Harvey Dent's wife, Gilda, claims to have been the first Holiday, and technically is, by murdering Alberto's father, Carmine Falcone, in the final issue of The Long Halloween, however, Dent himself is the final Holiday killer). Soon afterwards, the Hangman killings begin during the remaining parts of Year Two and most of Year Three.
The many victims of the Hangman Killer were all law-enforcement agency related, some straight, others corrupt, and they were important in leading to Harvey Dent earning his position of District Attorney, in some way or another. They are as follows:
- Chief Clancy O'Hara - O'Hara was the chief of the G.C.P.D., one of the few uncorruptible. While still a sergeant years ago, he and then-officer Stan Merkel were noted for capturing then-teenage Mario Falcone, who was prosecuted by then-Assistant District Attorney Harvey Dent. He was the first victim of Hangman, found hanging from the Westward bridge with a rope around his neck.
- Commissioner Gillian B. Loeb - Loeb was the Police Commissioner before being fired and replaced during the events of Year One. He was a friend to both Falcone and Sal Maroni, which made him so corruptible that no one prior to Batman: Year One would try to take him down. Found hanging in his own residence with the typical clue sheet being a personal sheet of paper marked "From the desk of Harvey Dent, D.A," which leads to Gordon believing for most of the story that Dent/Two-Face is the Hangman.
- Detective Flass - Once Jim Gordon's former police partner in Batman: Year One, Arnold Flass was one of the more corrupt officers on the force, only to get caught in criminal activity, fired and prosecuted for affiliating with the mob. Before his trial, he struck a plea bargain with prosecutor Harvey Dent to testify against Loeb for a lighter sentence. He was found dead outside, while on his cigarette break, of a strip club called "The Cheetah Room," where he was working as a bouncer to make ends meet. Judging from scratches and bruises on his hands, it appeared that he attempted to put up a fight in his final moments.
- Lieutenant Branden - A former head of the Special Weapons Unit of the GCPD, Branden was fired from the force for suspicions of being affiliated with corrupt Comm. Loeb, although according to Gordon, he was a zealot. Branden was hanged in a meat locker on New Year's Day.
- Sergeant Frank Pratt - Pratt worked for the SPW Unit up until his death and during Branden's tenure was his second-in-command. After attempting to kill Batman (who had come to him as part of his investigation into the Hangman killings) as retaliation for being punched through a wall during Batman: Year One, he was killed on Valentine's Day.
- Watch Commander Stan Merkel - A patrolman of downtown Gotham, Merkel was involved in a number of drug busts and hostage situations. Back when he was an officer, he was instrumental in bringing Mario Falcone to trial. Merkel was found dead on St. Patrick's Day, hanging on the former property of the house that originally belonged to Harvey and Gilda, making him the sixth victim. (He appears in the first issues of Batman Confidential, as well as throughout Batman: Year One and Batman: Night Cries)
- Commissioner Jim Gordon - Being one of the two survivors of Hangman, Gordon was nearly hanged to death while investigating the sudden activation of the Bat-Signal while he was in his office, but was cut down by Harvey Dent.
- Detective Henry Gustavson - Gustavson was the bodyguard of Gordon following the attempt on Gordon. He was murdered on Mother's Day and found by Gordon hanging over his car in the GCPD underground parking lot.
- Detective Mark O'Connor - A gifted marksman, O'Connor spent many years teaching use of firearms to cadets. One of the members of Gordon's Special Police Task Force, he was found dead hanging by a rope in the shower of his apartment on Father's Day. According to Batman, had he only been carrying his gun with him at all times, the Hangman would never have gotten him.
- Captain David King - Another of Gordon's "Untouchables," he was a trusted ally and investigator. While heading into the sewers to try and capture Two-Face, he ventured off alone from the group and was found hanging by a pipe, the date being the Fourth of July.
- Detective Laureen Wilcox - A newcomer to the G.C.P.D., Wilcox seemed to be a dilligent and articulate police officer with a dedication to upholding the law. She was important in the planning of and capture of Two-Face and bringing him to face trial. However, she was an informant to the Falcone family on payroll, leaking information to the acting head of the mob. During the trial, on Labor Day, she headed up to the courthouse via elevator, only to get hanged by the Hangman. Her walkie-talkie left a brief recording of her final moments that led Gordon to learning the true identity of the killer.
- Alberto Falcone - Formerly the killer known as Holiday, Alberto Falcone was the final victim killed by the Hangman, although he was not killed by a noose. Placed under house arrest, he was wounded and easily captured, then taken to the Falcone crypt, where he was suffocated with a pillow to death.
- Harvey Dent/Two-Face - The Hangman's main target was former D.A. Harvey Dent/Two-Face, who was captured and nearly hanged in the basement of Arkham Asylum during a deliberate arson attack on Gotham's sewers. Batman got there in time to rescue him and confront Hangman once and for all, making him the second survivor. Two-Face then kills the Hangman.
The arrival of the Hangman Killer sparked a gang war in Gotham City between the Falcone family, who were desperately trying to reclaim their hold on the city, the Maronis, who were on strained terms with the Falcones, the GCPD, and the "freaks" who would become the familiar Batman Rogues' Gallery. A number of people who were directly and indirectly involved also perished or injured during the Hangman's crime wave of nearly nine months.
- Angelo "Killer" Mirti- Sofia Gigante's personal bodyguard and former aide to her late father, Carmine "The Roman" Falcone. He was shot in the head by The Joker, after the Clown Prince of Crime invaded the Falcone summer residence.
- The Joker- Received a gunshot wound to the arm by Alberto, ostensibly to protect his sister (The Joker was close to shooting her in the head). He survived, was captured by Batman, and taken back to Arkham Asylum.
- John and Mary Grayson- Parents of Dick Grayson and two-thirds of the Flying Graysons acrobat team, they were caught in the middle of the gang war involving Tony Zucco, who was a capo in the Maroni family, and his extortion ring to get further up in the mafia. After blackmailing Haley's Circus owner and ringmaster "Poppa" Haley, he burned the trapeze ropes with acid, the same used to scar Harvey Dent, sending the Graysons falling to their deaths and leaving Dick an orphan.
- Tony "Fats" Zucco- The gangster responsible for killing the Graysons was directly involved in the criminal doings of the Maronis and Falcones. Batman and Dick (training to be Robin) tracked him down at his headquarters at the Ox Club, "Gentlemen's Club" and confronted him. He died of a heart attack, confessing his crimes and information about the Falcones.
- Janice Porter- The no-nonsense District Attorney appointed after Harvey Dent, she was responsible for arranging Alberto Falcone's release from Arkham and had a distrust for Batman. Revealed to be Dent/Two-Face's lover, she was captured and taken to Two-Face's lair in the sewers, where he shot her after realizing that she was in love with him, and although their relationship had apparently been sexual in nature, Two-Face claimed to still be a "married man". This killing marks one of the few murders Dent/Two-Face has performed in which he does not flip his scarred coin first, meaning his two personalities are, for once, in agreement about what has to happen.
- Pino and Umberto Maroni- The sons of deceased gangster Sal Maroni, they were attempting to win respect with the Falcone family and then strike them down upon gaining control (although Zucco's dying words revealing them to be twins suggests Two-Face may have been using them for his own ends). Two-Face, cleaning up loose ends as the Falcone empire crumbles, shot both of them at two in the morning with two shots each to the chest, killing them in their own restaurant on Columbus Day.
- Edward Skeevers- One of the few trusted Falcone family friends, Skeevers was the consigliere following the death of his predecessor Milos Grappa. He was murdered by Mr. Freeze during the Rogues Gallery's Columbus Day Massacre.
- Bobby Gazzo- Head of the mafia families in Metropolis, he is killed by the Joker during the Columbus Day Massacre, shot to death in his hotel room.
- Lucia Viti- Carmine Falcone's niece and de facto heir of her deceased mother's Chicago crime organization, she is killed by Poison Ivy as part of the Columbus Day Massacre.
Batman enlists the help of James Gordon, but is still left troubled after Harvey Dent is horribly scarred by a criminal he is prosecuting, bringing out into the open his latent multiple personality disorder and transforming him into a violent crime boss. Now known as Two-Face, Dent wreaks havoc on Gotham and forces Batman to confront his former ally.
In the end, the Hangman is revealed to be Sofia Falcone Gigante, daughter of the late crime boss. After seeing her father murdered by Two-Face, Sofia charges forward and is restrained by Catwoman. During the struggle, Catwoman scars the right side of Sofia's face and the two tumble out a window. In Dark Victory Catwoman tells Batman that when Sofia fell, her bolo/whip became tangled around Sofia's neck. The whip then caught on a stone gargoyle and threw Sofia through another window, and the broken glass sheared off the right side of her face. Catwoman (who believes that she is Falcone's illegitimate daughter) follows Sofia to Europe where she undergoes plastic surgery to restore the damage done to her face.
Sofia, who appears in a wheelchair for the majority the story, is shown with the left side of her face scarred, which we find she did herself after the surgery to be closer to her father's spirit (who was himself scarred by Catwoman in Batman: Year One). Catwoman tells Batman she was able to find the doctor who treated her ruined face, but not one who treated her paralysis. This is because her paralysis was a ruse, in order to appear weak and avoid being a suspect in the Hangman murders (interestingly in issue #8, "Battle", the Joker deduces this, but is ambushed by Alberto and then Batman before he can truly test his theory). Her final target is Two-Face himself, although Batman saves him, and Dent kills Sofia with a gunshot to the head.