Lee Chun-jae, who is serving life imprisonment for a similar murder, admitted in October his involvement in 10 crimes linked to the serial murder case after DNA tests identified him as the key suspect in at least five cases.
Ten women were killed in the rural village of Hwaseong, south of Seoul, between 1986 and 1991 in the country's worst serial murder case. The crimes, targeting women aged 13 to 71, became notorious for their brutality and the disappearance of the murderer.
"Lee Chun-jae's confession (to the eight murder) mostly coincides with circumstances at the scene," an official at Gyeonggi South Provincial Police Agency told a press briefing in Suwon, south of Seoul.
Police said they tentatively reached the conclusion based on a confession by Lee that elaborately and coherently described the circumstances of the scene and the victim.
The confession, however, has raised suspicions that police wrongfully charged an innocent man, surnamed Yoon, as the culprit behind one of the cases, which they previously concluded was a copycat crime.
Yoon, despite denying any involvement in the case, was charged with the murder of a 13-year-old girl in 1988 in a case that was considered the eighth of the 10 murders.
Yoon was sentenced to life imprisonment and spent 20 years in prison until he was released on parole in 2009.
Following news reports that Lee had claimed responsibility for the eighth crime, the 52-year-old filed for a re-trial of the case at a Suwon district court on Wednesday. (Yonhap)