A man’s car is hit by a stranger who kills him when he gets down to take pictures of the damage for claiming car insurance. Jung Tae-suk is an honest cop who goes through the crime scene and suspects it to be the work of a serial killer, but his senior does not believe him.The Gangster the Cop the Devil full Movie.
Gangster Jang Dong-soo is on his way home after a meeting when the same killer hits his car and eventually tries to kill him. A brutal fight ensues, leaving both of them injured. Finally, the killer escapes after knocking Dong-soo with his car. Dong-soo is admitted to the hospital, and his henchmen assume that the attack was committed by a rival gang, whom they counter-attack. However, Dong-soo believes the killer was not a rival gang member as his moves seemed to be random and purposeless. Tae-suk visits Dong-soo at the hospital and asks him to cooperate so that he can catch the killer for him, but Dong-soo does not comply. Instead, Dong-soo orders his men to find the killer through a sketch, and they manage to find his car and a knife. Dong-soo eventually informs Tae-suk of the findings, and they decide to team up to catch the mysterious killer. Dong-soo agrees to provide manpower and cover expenses — but on the condition that the killer belongs to the one who finds him first. Dong-soo wants to kill him for revenge while Tae-suk wants to arrest him in order to solve five connected murder cases and then eventually get promoted.
Meanwhile, Dong-soo orders his right-hand man, Kwon Oh-sung, to kill his rival Heo Sang-do with the killer’s knife that already has the blood imprints of the killer’s previous victims. An enraged Tae-suk gets into a fight with Dong-soo upon learning what he has done as the killing is confirmed to be the serial killer’s work and the case would get transferred to the Major Case Squad. Dong-soo visits Sang-do’s funeral where the killer also turns up informing Sang-do’s second-in-command man that it was Dong-soo who actually killed Sang-do with the killer’s knife.