Prosecutors on Thursday questioned the former lead prosecutor in the eighth of the Lee Chun-jae serial killings that occurred in the 1980s and 1990s.

The former prosecutor was booked Tuesday on charges of abuse of power including unlawfully detaining the man who would later be convicted of the crime, surnamed Yun. Yun filed for a retrial after Lee Chun-jae, who is already in prison for raping and killing his sister-in-law, admitted to the serial killings.

While the former prosecutor will not face criminal punishment as the statute of limitations has already expired, police pushed ahead with the charges to identify alleged wrongdoings by law enforcement officials.

But the efforts to find the truth in the case hit a stumbling block as the court turned down the police request for a warrant to raid the office of National Archives of Korea, which is in possession of body hairs found at the scene of the eighth case in the Lee Chun-jae killings. Police believe they are key evidence.

The court reportedly said establishing criminal responsibility was not viable since the statute of limitations has expired. The archive agency received the evidence from the National Forensic Service in 2017 and 2018.

By Choi Si-young (siyoungchoi@heraldcorp.com)