Police said last week that Lee confessed to five additional murders and some 30 rapes and attempted sexual assaults.

In the 11th round of questioning on Oct. 4, Lee told police they included the 1988 rape-murder of Park.

But another man, surnamed Yun, was convicted for the murder, sentenced to life and served 19.5 years in jail before being released on parole in 2009. Yun was in his early 20s at the time of the offense.

Police said Yun admitted guilt during questioning, and that he was pinned as a key suspect after a forensic test of pubic hair found at the scene suggested similarities with his, although it did not confirm a match. Police added Yun was the only suspect to have the analysis done on his hair sample.

Court records show that Yun appealed the ruling at the time, alleging that police extracted a false confession through torture.

According to the 1990 sentencing memo, Yun claimed he “gave false testimony due to severe torture inflicted on (him) by police.”

Gyeonggi Police said they are in the process of “weighing the veracity of both Lee and Yun’s claims.”

Police said Yun pleaded innocence in two meetings last week, and that they are speaking with the authorities who were in charge of the investigation at the time.

On Wednesday, a lawyer representing Yun said in a Facebook post that his client intends to bring the case back to court. If he is exonerated, Yun is entitled to around 1.7 billion won ($1.4 million) in compensation from the state.

A team of profilers grilled Lee for the 14th time on Thursday. The police agency's Superintendent General Ban Ki-soo said Lee has given “substantial details” about the murder of the 13-year-old, enough to “reasonably suspect” him of responsibility.

In what are known as the Hwaseong serial killings, at least 10 girls and women were raped and murdered. The case remained a mystery until last month when a new DNA technology connected Lee to three of the murders. Lee is currently serving a life term in a Busan prison for the 1994 rape and murder of his sister-in-law.

By Kim Arin (arin@heraldcorp.com)