He stages public visits to the homes of family members to beg for forgiveness, and even visits Choi at his precinct. His book becomes a bestseller because of the author’s charming looks and his claims of repentance for his crimes. His book contains detailed descriptions of the murders, and he even displays a wound in his shoulder where he says Choi shot him, with the bullet still lodged there. Two years later, Choi is alerted to the news that a man called Lee Doo-seok ( Park Si-hoo) has released a book titled I Am the Murderer, claiming responsibility for the murders that took place 17 years ago. Choi rushes to his apartment, only to see Jung throw himself off a roof and land through the windshield of a passing bus. He suddenly receives a worrying call from Jung Hyun-sik (Ryoo Je-seung) a family member of one of the victims. Choi is now an alcoholic, haunted by his failure to solve the case.
The film begins in 2005, on the day the 15-year statute of limitations expired, thus rendering prosecution impossible.
Before the killer vanished however, Choi managed to shoot him in the shoulder. He managed to hunt down the killer, but lost him after a fierce fight that left Choi nearly dead and permanently scarred.
Choi Hyeong-goo ( Jung Jae-young) is a detective who was in charge of hunting down a serial killer who claimed the lives of 10 women from 1986 to 1990, and whom Choi suspects is responsible for the kidnapping and possible murder of another.