Photo/Illutration Yoon Seong-yeo, 53, center, is congratulated at the Suwon District Court in Suwon, South Korea, on Dec. 17. (Yonhap via AP)

SEOUL--A South Korean man who spent 20 years behind bars for a murder he didn’t commit has cleared his name in court after one of the country’s most notorious serial killers confessed to the 1988 rape and murder of a 13-year-old girl.

Yoon Seong-yeo, 53, had been sentenced to life in prison and was released on parole in 2009. He listened quietly as Judge Park Jeong-je of the Suwon District Court apologized to him on Thursday on behalf of the judiciary for causing him "immense physical and mental pain” because of the wrong verdict.

“The defendant is innocent,” Park announced. Yoon’s acquittal prompted thunderous applause from his supporters in the gallery.

“I hope no one ever has to go through what I went through and that all cases receive fair trials,” Yoon told reporters after the ruling.

Yoon, then a 22-year-old mechanic in the farming town of Hwaseong, was arrested in July 1989 after police accused him of raping and murdering the girl in September 1988.

Between 1986 and 1991, 10 women of various ages were found brutally raped and murdered in the Hwaseong area, and Yoon’s arrest came as police faced immense public criticism over their failure to identify the serial killer.

Police had concluded that Yoon committed a copycat crime. Yoon pleaded not guilty, saying that police investigators forced him to confess to a crime he didn’t commit. The Suwon District Court handed him a life sentence in October 1989 which was upheld by the Supreme Court in May 1990.

It seemed that the Hwaseong killings would remain unsolved until police announced last year that Lee Chun-jae, a man who was serving a life sentence for murdering his sister-in-law in 1994, confessed to the murders, including that of the 13-year-old girl. Yoon filed for a retrial in November last year.

Lee testified during Yoon’s retrial last month and repeated his confession.

The Hwaseong killings inspired the 2003 movie “Memories of Murder,” the breakout work of director Bong Joon Ho, who won this year’s Academy Award for best film for his dark comic thriller “Parasite.”