That victim was (also spelled Kim Tae-chon). At the time, Kim was the leader of a violent underground gang known as the "The Pope Organization" or the "Yangsan-dong Mob."
The film is visceral, brutal, and strangely elegant in its violence. It tells the story of three men: Jang Dong-su (Don Lee), a mob boss who gets stabbed by a serial killer and survives; Jung Tae-seok (Kim Moo-yul), a hot-headed detective obsessed with catching the killer; and "K" (Kim Sung-kyu), the ghost-like murderer who connects them. The plot hinges on an unbelievable truce—a gangster and a cop shaking hands to hunt a monster. is the gangster the cop the devil based on true story
| Element | In The Gangster, The Cop, The Devil | In Real Life (Yoo Young-chul / Kim Tae-chon) | | :--- | :--- | :--- | | | Serial killer stabs mob boss; boss survives. | Serial killer attacks mob boss with crowbar; boss wins the fight. | | The Alliance | Gangster and Cop form an official, secret pact to catch the killer. | No alliance. The police were already investigating. The gangster hunted the killer alone. | | The Motivation | Cop wants justice; Gangster wants revenge for his wounded pride. | Gangster acted purely out of pride and territory protection. | | The Ending | The cop arrests the gangster after the killer is caught. | The gangster was already a wanted criminal. Both the killer and the gangster went to prison separately. | | The Killer | A young, handsome, smiling psychopath who kills randomly. | A middle-aged, awkward construction worker with specific hatred for rich people and sex workers. | | The Daughter | The killer targets the gangster’s daughter. | No such relationship existed. Yoo targeted strangers. | Why Did the Filmmakers Change the Story? Director Lee Won-tae had a specific goal. He wasn't making a documentary about Yoo Young-chul; he was making a genre film about the blurry line between law and crime. The true story provided a fantastic hook —a gangster hunting a killer—but it lacked narrative symmetry. That victim was (also spelled Kim Tae-chon)
The real Yoo Young-chul was far more eccentric and motivated by specific class rage. He was a disgruntled construction worker who hated the wealthy and, later, hated sex workers because he blamed them for his own sexual failings. He was not a quiet, calm phantom; he was a chatty, narcissistic, and angry man. The plot hinges on an unbelievable truce—a gangster
When the police interrogated Yoo Young-chul, the killer confirmed the story. He admitted he was terrified of Kim and had avoided the Gangnam district entirely after that beating. In the film, the serial killer "K" is a faceless, spectral figure who kills for a twisted sense of pleasure. He has no clear motive, lacks empathy, and is always smiling. This character is almost entirely the invention of screenwriter Kim Min-seok.
However, one detail the film borrows accurately is the . In the movie, the gangster (Don Lee) deliberately rams his car into the killer's vehicle to disable him. In reality, Yoo Young-chul was caught because he rammed his car into a police surveillance vehicle by accident, leading to his arrest. The filmmakers inverted this—giving the gangster the agency to crash the car. Fact vs. Fiction: The Definitive Split To help clarify, here is a direct comparison between the film’s plot and the historical reality: