Even the victim's real name and age... Why was a report on a ”random murder case” leaked online? = South Korea

The police have begun to investigate the circumstances of the Suncheon random murder case after a situation report prepared by the police and local government on the day of the crime was leaked online.
The document contains personal information such as the name and age of the deceased, as well as details of the incident that have not been released to the media.
The report was compiled by the Jeonnam National Police Agency's Violent Crimes Investigation Division and Suncheon City Safety General Affairs Division, among others.
The two reports that are believed to have been submitted are official documents that are prohibited from being leaked to the public. Each report contains personal information such as the real names and ages of not only the suspect Park Dae-seong (30), but also the victims, as well as information that was not made public to the media.
The report contains details of the incident that have not been made public. Police believe that the report was leaked on the 26th of last month, the day of the incident. After conducting a pre-charge investigation (undercover investigation), the police confirmed who originally spread the information.
If the investigation is successful, the police plan to turn it into an official investigation on charges of leaking official secrets or violating the Personal Information Protection Act. Prior to this, Park was arrested at around 12:44 a.m. on the 26th of last month at Cho
Park was arrested and sent to the prosecution on suspicion of murder after stabbing a 18-year-old man, A, multiple times with a deadly weapon while he was walking down the street in Jeorye-dong. After drinking alone at a delivery restaurant he owns,
He went outside with a weapon and followed A, a man he did not know, for about 800 meters before committing the crime. The police decided to take into consideration the brutality of the method, the public's right to know, and the serious damage caused, and
The identity and mugshot of suspect Koo were published on the website of the South Jeolla Police Agency on the 30th of last month.