Memories of Murder

In October 1986, two women are found raped and murdered on the outskirts of a small town. The local police department, inept and ill-equipped to deal with such a serious case, is quickly overwhelmed. Fabricating evidence and employing violent methods, detectives Park Doo-man and Cho Yong-koo coerce Baek Kwang-ho, a scarred and cognitively disabled young man, into a confession. Seo Tae-yoon, a detective from Seoul with more comprehensive training, determines that Baek is not capable of committing the crimes. After closely studying the reports, he discovers the decomposed remains of a third victim, and deduces that the killer struck on rainy nights and targeted women wearing red. Inspector Kwon Kwi-ok, the police force's under-appreciated female officer, observes that the same obscure song was requested on the local radio station on the night of each crime.

Despite a stakeout, on the next rainy night, the killer murders a woman near a gypsum mine. At the next stakeout, Park, Cho and Seo apprehend a miner masturbating near the crime scene, but his forced confession does not fit the details of the crime. Recalling a story told by two local schoolgirls, Seo investigates the school outhouses and finds the killer's only surviving victim, a traumatized woman living nearby. She divulges additional details, including the fact that the killer has soft hands. The killer strikes again soon after.

Park and Seo's investigation leads them to Hyeon-gyu, a clerk at the mine from whom the song requests originated. Seo notices that Hyeon-gyu has soft hands and moved to the town around the time of the first murder, but otherwise has no concrete evidence. Recalling Baek's forced confession, they realize that he was a witness to one of the murders. Park and Seo visit the restaurant run by Baek's father and encounter a drunken Cho, who has been suspended for attacking Hyeon-gyu. Angered by other patrons' mockery, Cho instigates a brawl. A panicked Baek runs out, stumbles in front of a passing train and is killed before Park and Seo can question him.

The coroner discovers semen in the latest victim, but as South Korea lacks the capability to conduct forensic DNA analysis, the police are forced to send the sample to the United States to compare it against Hyeon-gyu's. Meanwhile, an untreated wound in Cho's leg inflicted by Baek during the brawl develops tetanus, forcing it to be amputated.

On the next rainy night, Seo surveils Hyeon-gyu but dozes off and loses track of him, and a schoolgirl is murdered later. An enraged Seo attacks Hyeon-gyu the next day and attempts to force a confession at gunpoint, just as Park arrives with the results of the DNA test, which prove inconclusive. As Seo tries to shoot Hyeon-gyu, Park stops him and allows Hyeon-gyu to leave.

In 2003, Park is married with two children and works as a salesman. Passing by the first crime scene one day, he stops at the ditch where the victim was found. A young girl tells him she saw a man in the exact place, reminiscing about something he had done there a long time ago. When asked what the man looks like, she answers that he looks ordinary. Shaken by the realization that the killer is still out there, Park stares into the camera.