His admission came during nine rounds of questioning by profilers after police officially announced him as the prime suspect in the high-profile cold case on Sept. 19. Police said that his DNA match in three of the rape-murders led to the identification.

A team of veteran profilers questioned Lee in Busan Prison for the ninth time on Tuesday. While he had denied his involvement in the crimes in the first five rounds of questioning, profilers worked on building a rapport with the suspect over the two-week period and got him to confess, the police said.

The police said Lee changed his position after forensic tests last week revealed his DNA matched that found in another rape-murder, a fourth confirmation to date. Police said they have requested the National Forensic Service for a test of DNA samples found in the remaining crimes.

Despite his admission of guilt, police said they are still verifying his claims due to certain irregularities in his account.

Ban Ki-soo, superintendent general of Gyeonggi Nambu Provincial Police Agency, said the verification is necessary as Lee’s testimonies are based on his memory, “which may have been warped over time.”

The police declined to specify the additional crimes that Lee admitted to having committed. On Sept. 25, Gyeonggi Nambu Provincial Police Agency’s cold case team said they were looking into the possibility Lee may be connected to other unsolved crimes that occurred in Hwaseong from the late 1980s to early 1990s.

Although the statute of limitations expired in 2004, authorities said they did not close the case in which at least nine girls and women -- ranging in age from 13 to 71 -- were brutally raped and killed.

Police said they would review the possibility of changing Lee’s status from suspect to accused, as they inch closer to cracking the cold case.

By Kim Arin (arin@heraldcorp.com)