Four police officials, including a former Seoul police chief, were indicted Tuesday on charges of negligent homicide in the death of an activist farmer due to injuries caused by a police water cannon.

In November 2015, Baek Nam-ki fell unconscious after he was shot directly by a police water cannon during an anti-government rally. The farmer in his 60s was in a coma before he died of acute renal failure in September 2016. 

The Seoul Central District Prosecutors' Office indicted Goo Eun-soo, then-commissioner of the Seoul Metropolitan Police Agency, Shin Yun-kyun, then-chief of the 4th riot squad, and two low-level officers who operated the water cannon. 

They will face trial without detention.

The prosecution claimed that their negligence of duty was responsible for the farmer's death, which stirred up a huge public uproar against the police's excessive use of force on protesters.

A probe found the riot police had failed to follow rules that ban the firing of water cannons directly at a person above the chest. Baek was hit directly in the head by the high pressure jet.

It accused the police of neglecting their duty to use force with the utmost caution.

The probe also revealed that a device that controls the water pressure was malfunctioning at the time, raising the possibility that it could have been fired at a pressure exceeding the legal limit.

The police agency denied responsibility, saying it had followed every legal procedure. 

The prosecution did not file charges against Kang Sin-myeong, national police chief at the time of the incident, saying he was not directly involved in the operation.

Baek's family expressed regret over the probe result, insisting that Kang should also be held accountable. They called on the prosecution to hasten its investigation into Seoul National University Hospital over alleged doctoring of its initial report on Baek's death, which stated he died from an illness.

In June, the hospital revised its report and said his death was from an "external cause." (Yonhap)