The movie accurately captures the bureaucratic frustration of the Korean police force at the time. Jurisdictional battles, lack of advanced profiling tools, and internal corruption often slowed down investigations, which explains why the fictional Detective Jung felt forced to look outside the law for help. Summary: What is Fact and What is Fiction? Element in the Movie Real-Life Basis
Detective Jung Tae-suk realizes that the mob boss's attacker is the same serial killer he has been tracking. Because the police force is choked by bureaucracy and corruption, the cop strikes a secret deal with the gangster: whoever catches the killer first gets to deal with him by their own laws (legal trial vs. mob execution). They pool together police databases and underworld manpower.
You're referring to the popular Indian web series "The Gangster, The Cop, The Devil"! is the gangster the cop the devil based on true story
While the film focuses on the unlikely alliance, the core inspiration for the antagonist, "the Devil"—a serial killer known as Kang Kyung-ho (played by Kim Sung-kyu)—draws from the terrifying wave of serial killings that plagued South Korea in the early 2000s, specifically those linked to infamous murderers like Yoo Young-chul.
As noted by multiple reviewers, the film's opening titles state it is based on a true story. The film is set in August 2005, and this claim has led many to search for the exact events that inspired it. The film's English title, and its Korean title "Aginjeon" (meaning "The story of evil people"), point to a tale where morality is fluid and every character is, in some way, an antagonist. Element in the Movie Real-Life Basis Detective Jung
| Plot Element in the Film | Real-Life Basis | | :--- | :--- | | | Largely Fictional. This specific alliance is a dramatic invention for the film. | | A serial killer attacks a powerful gangster, who survives the assault. | Largely Fictional. There is no known case of this happening. This event is the story's main fictional catalyst. | | A serial killer who murders strangers, including by staging a minor car crash. | Partially Inspired. This is inspired by the ruthless and random nature of killers like Yoo Young-chul . | | The story takes place in 2005. | True. The 2005 Cheonan serial murders provided the historical backdrop. | | A high-profile serial murder case grips a community. | True. This reflects the very real, widespread fear that gripped the nation during the crime sprees of the early 2000s. |
So, to answer your question: while "The Gangster, The Cop, The Devil" is not a completely factual account, it's based on a true story and draws inspiration from real-life events and individuals. They pool together police databases and underworld manpower
The partnership between Jang Dong-su (the gangster) and Jung Tae-seok (the cop) is purely a product of creative screenwriting. There is no documented case in modern South Korean history where a mafia boss formally allied with law enforcement to track down a killer, especially one who had already tried to murder him. This dynamic serves a powerful thematic purpose. It allows the film to explore a morally grey world where traditional justice fails. The cop is too reckless to play by the rules, and the gangster is too proud to be a victim. Their alliance is one of convenience and mutual respect born from a common enemy. This narrative device is a classic of crime cinema—the "enemy of my enemy" trope—and while it makes for gripping drama, it has no direct factual counterpart.
: In real life, cooperation between a crime boss and a detective is rarely as direct or formal as the "alliance" seen on screen.
The "Devil" in the movie is portrayed as a calculating, random killer who strikes without a clear motive or consistent victim profile, often staging scenes to look like traffic accidents. This randomness mimics the chilling tactics used by real-life South Korean serial killers who targeted vulnerable individuals in residential areas during that period. The Real-Life Connections