He spent 20 years in prison for murder. Then someone else confessed to the same crime

Updated 1533 GMT (2333 HKT) May 24, 2020

(CNN)In the fall of 1988, a 13-year-old was raped and murdered in her bed.

The crime would have been shocking anywhere else, but in Hwaseong, then a rural area near South Korea's capital Seoul, murders like this were happening with disturbing regularity. She was the eighth female to be murdered there in two years.
Nearly a year after the teen was killed, police arrived at the house of a 22-year-old repairman, just as he was about to eat dinner.
"What's this about?" Yoon, whose full name is not being published due to a South Korean law that protects the privacy of suspects and criminals, remembers asking. "It won't take long," he says police replied.
The officers took him to a small interrogation room with a single table at the local police station where they questioned him for three days about the 13-year-old's rape and murder. Eventually, they extracted a confession.
Yoon told police that on the night of the murder, he had gone for a walk to get some air, according to records of his confession obtained from his attorney. During the walk, he had to stop several times to rest -- his childhood polio had left him with a limp so bad that he had been exempted from compulsory military service. Around midnight, Yoon saw a house with a light on and felt a sudden "urge for rape," he told police, according to transcripts of his confession. He climbed into the house and attacked the young girl, although he told police he knew the parents were asleep next door.
Afterward, he burned his clothes and went home, according to the confessions.
Little is known about the girl and her family, who have never spoken to media.
Yoon's story is somewhat clearer: He was convicted of raping and murdering the 13-year-old girl and sentenced to life in prison, though his sentence was later reduced on appeal. He was released after 20 years in prison.
The problem is, Yoon says he didn't do it.

Where everyone knows everyone

Before 1986, Hwaseong wasn't the sort of place where violent crime happened. About 226,000 people lived in the area, scattered among a number of villages between forested hills and rice paddies.
One of those villages was Taean-eup, where Yoon lived. In the 1980s, Taean-eup was a bustling community with rice-wine bars and Korean-style coffee shops where locals liked to gather and gossip. Many people worked in the nearby factories, many of which created electrical goods, such as light bulbs, remembers Hong Seong-jae, who ran the farming machine repair store where Yoon worked. Others worked as rice farmers, and even those who lived downtown kept cows for milk. Everyone in Taean-eup knew each other, Hong said. Before the murders, there was no real crime to speak of -- only the odd robbery or break-in.
"But we were all so poor, there wasn't much to be lost," Hong said.
But in 1986 that changed. In September that year, a woman was murdered, the first in a series of killings that came to be known as the Hwaseong murders. By 1991, 10 women and girls had been killed in the Hwaseong region, including the 13-year-old killed in her bed. In all of the cases, the victims had been sexually assaulted, and in many of the cases, an article of their clothing, such as stockings or a blouse, had been used in the killing. The victims included housewives, schoolgirls, and a department store worker, according to Ha Seung-gyun, who was involved in the investigation.
The youngest were teenagers, the oldest were 71 years old, according to police records.
No one seemed safe.
As the murders kept happening, the people of Hwaseong grew more afraid.