Lee Chun-jae, 56, told investigators that he was responsible for the killings of nine women from 1986 to 1991 in Hwaseong, South Korea after DNA evidence from four of the crime scenes linked him to the string of murders, The New York Times reported.
Police say he also confessed to the rape and murder of an additional five women and the rape or attempted rapes of at least 30 more women.
Chun-jae was first named as a suspect last month after Seoul’s senior police officer, Ban Gi-soo, said technological improvement of DNA analysis allowed authorities to extract samples from the evidence that wasn't possible at the time of the cases.
Between 1986 and 1991, nine women between the ages of 13 and 71 were found slain in Hwasong, a city just south of Seoul. All had been raped and all were found bound by their own stockings and clothing at sites within a two-mile radius.
Chun-jae is serving a life sentence for the 1994 rape and murder of his sister-in-law.
According to local media, he will likely not be prosecuted for the murders, despite his confession, because of the statute of limitations expiration in 2006.
It is believed that two of the killings took place before the murder of his sister-in-law and the rest followed after.