Seoul, Jul 2 (IANS): South Korean police on Thursday closed the country's longest-standing cold case involving a series of brutal rapes and murders that began more than three decades ago.

Gyeonggi Nambu Provincial Police Agency concluded in a briefing that Lee Chun-jae killed 14 women, most of them rape-murder cases, and raped nine others, wrapping up its one-year investigation into him and his killing and raping spree that terrorized the country in the 1980s and 90s, reports Yonhap News Agency.

Lee was found responsible for all of the 10 killings of women aged 14 to 71 in Hwaseong, Gyeonggi province, from 1986-1991 in what is known as the worst serial murder case in the country's modern history, the police said.

All but one of the killings had long remained an unsolved criminal mystery.

In the eighth of the 10 murders in chronological order, a man surnamed was convicted in 1989 of raping and killing a 13-year-old girl at her home on September 16, 1988.

He was released on parole in 2009 after serving 20 years in prison. He applied for a retrial last year as Lee emerged as a key suspect in the case.

In addition to the infamous serial murder case, Lee was also blamed for four other murder cases that occurred in December 1987, July 1989, January 1991 and March 1991 after the reinvestigation.

Police said Lee admitted to a total of 34 rapes and robberies, but only nine cases, which could be backed by forensic evidence, were confirmed to have been committed by him,Yonhap News Agency reported.

The reinvestigation began in July last year when Lee's DNA appeared to match samples recovered from some old objects from the murder scenes.

Lee was serving a life sentence in prison at that time in the southern port city of Busan for raping and killing his sister-in-law.

As the statute of limitations on all the cases has already expired, however, police said, Lee cannot be prosecuted for any of the crimes.

"We offer an apology for those damaged during the police's excessive investigation into the Lee Chun-jae Serial Murder Case," Bae Yong-ju, chief of the police agency, said during the briefing.