Kim Hyung-ryul, a senior official at the Gyeongbuk Provincial Police Agency in Andong, about 190 kilometers southeast of Seoul, announces the result of an investigation into a Marine's death during a search operation, at a press briefing on Monday. (Yonhap)

The police said on Monday they have decided to clear a former 1st Division Commander Lim Seong-geun of negligent homicide charges related to the death of a Marine conscript during a search operation in a stream following torrential rains last summer.

Concluding its year-long investigation, the Gyeongbuk Provincial Police Agency forwarded six others to the prosecution for indictment, saying that Lim was excluded because he had not been in a position to issue a direct "underwater search order," which investigators identified as a key cause of the conscript's death. Lim was the highest-ranking military personnel involved in the case and has been at the center of allegations of interference in the military's initial inquiry into Chae's death.

The young Marine conscript, Cpl. Chae Su-geun, 20, was swept away during a search for missing flood victims in a stream swollen with floodwater in Yecheon, North Gyeongsang Province, on July 19, 2023. He was found dead half a day later. The conscript's death sparked suspicions that he had been forced by his superiors to push ahead with the risky rescue operation without proper safety measures in place.

The case also sparked a major political scandal when suspicions rose that President Yoon Suk Yeol himself had ordered the military to scale down its investigation into Chae's death.

According to the police, the direct cause of Chae's death was the battalion commander's arbitrary decision to change the order for the conscripts to enter the stream up to their waist instead of the initial command to remain at boot-high water levels.

"Unclear directions for the search, combined with a lack of communication, influenced" the battalion commander's arbitrary decision to change directions, said Kim Hyeong-ryul, the chief investigator at Gyeongbuk Provincial Police Agency.

The other six military field commanders were referred to the prosecution as they did not provide clear instructions and communication regarding search guidelines, according to Kim. They also insufficiently considered the weather conditions and unit's lack of experience during operational deployments, and failed to implement necessary safety measures, the police said.

The presidential office responded that it respects the result of the police investigation. "It seems that the substantial truth uncovered by the police is quite different from the suspicions that have been raised so far," a senior presidential official told reporters. "We hope the Corruption Office for High-ranking Officials will promptly wrap up the investigation and clarify the facts," said the official.

Last week, the opposition-led National Assembly passed a bill mandating a special counsel probe of the military's investigation into Chae’s death, alleging that the investigation had faced external interference from then-Defense Minister Lee Jong-sup and President Yoon. A similar bill was vetoed by Yoon during the Assembly's 21st session.

The ruling People Power Party on Monday urged Yoon to veto the bill. PPP floor leader Rep. Choo Kyung-ho argued that the bill, pushed by the main opposition Democratic Party of Korea, is unconstitutional and lacked bipartisan support.