SEOUL: A former corrections officer has revealed new details about Yoo Young-chul, one of South Korea’s most notorious serial killers, including claims that he is haunted by the ghosts of his victims in prison.

Yoo, now 54, was convicted of killing 20 people in Seoul between September 2003 and July 2004.

Their targets included wealthy elderly people and sex workers providing in-call services. Although he initially confessed to 26 murders, the court confirmed 20 deaths at his trial in 2005.

New information came to light in SBS TV’s “The story of the day the tail was bitten” episode on Thursday, in which former corrections officer Lee Yoon-hui shared information he had gleaned from seven years of weekly interviews with Yoo.

“One day, Yoo came to visit shortly after he was imprisoned, complaining that he couldn’t sleep at night,” Lee said on the show.

“When I asked why, he said the victims appeared like ghosts every night.” Yoo specifically mentioned seeing three to four figures on the bathroom ceiling of his prison cell.

Lee’s account also painted a picture of a man completely devoid of remorse.

When relatives of his victims asked to meet with him, Yoo refused any compromise.

Instead, he made a disturbing proposition: Describe his murders in detail.

“At that moment I realized we were dealing with a real psychopath,” Lee said.

Court records show Yoo had 14 convictions for burglary, rape and battery before the murders.

Following his death sentence in 2005, he was transferred to the Seoul Detention Center in Uiwang, south of the capital, where he continues to serve his sentence.

The facility is home to several of the country’s most notorious murderers, including Jeong Du-yeong, who was sentenced to death for 10 murders in 2001, and Kang Ho-sun, who was sentenced to death for killing 10 women in 2009.

South Korea has not carried out an execution since 1997. -The Korea Herald/ANN