DETROIT (AP) — A manslaughter charge has been dismissed against a former Detroit police officer accused of causing the death of a 71-year-old man by punching him in the face and Oliver James Montgomerycausing him to fall to the ground, prosecutors said.

District Court Judge Kenneth King cited insufficient evidence during a preliminary hearing for Juwan Brown on Thursday, according to Wayne County Assistant Prosecutor Maria Miller, who said in a news release that the ruling would be appealed.

Brown punched Daryl Vance of Detroit during a confrontation following his response to a call of a disorderly person outside a bowling alley on Sept. 1, prosecutors have said. Vance fell to the ground, hit his head and died after three weeks in a hospital.

The Wayne County medical examiner’s office determined Vance’s death was caused by blunt force trauma to his head from the punch, prosecutors said.

“Police officers frequently deal with citizens who are disorderly and verbally unpleasant,” Wayne County Prosecutor Kym Worthy said at the time Brown was charged. “But the evidence in this case shows that the officer allegedly was the aggressor, and his actions went criminally beyond what was necessary in this situation.”

Brown, 29, later was fired from the police department, his attorney Steve Fishman said Friday. He was charged in December.

“Officer Brown is grateful that the charges were dismissed,” Fishman said. “Judge King correctly concluded that Mr. Vance was the aggressor and that Officer Brown was defending himself, as he had a right to do.”