South Korea’s police chief apologized for the death of a protestor who died after being knocked down by a water blast during an anti-government rally.

Lee Cheol-seong, head of the National Police Agency, said he was offering his “full and sincere condolences” to the family of Baek Nam-gi, the activist farmer who died last September as a result of injuries he sustained while protesting against former President Park Geun-hye in 2015.

“It should not be repeated that the police’s excessive use of force causes harm to people,” Lee said at a press conference Friday. He said police will no longer use water cannons at street protests. 

The apology came 581 days after Baek was knocked unconscious by a blast from a police water cannon and a day after Seoul National University Hospital -- where Baek spent 10 months in a coma before his death -- made a rare correction in his death certificate to change his cause of death from illness to “an external cause.”

Kim Yon-su, vice president of SNUH, told reporters Thursday that Baek’s death was caused by a cerebral hemorrhage caused by a direct blast from a water cannon, a correction made following a monthslong discussion by the hospital’s ethics commission.

Doctors had initially stated that his death was due to kidney failure, sparking backlash from Baek’s family and civic groups.

Critics have long argued that the doctors, possibly under undue pressure, betrayed their professional conscience so the authorities would not appear responsible for Baek’s death. The hospital’s chief at that time, Suh Chang-suk, served as a personal doctor to President Park Geun-hye in 2014 and has headed the hospital since June last year.

By Bak Se-hwan (sh@heraldcorp.com)