OAKLAND -- Involuntary manslaughter charges have been filed against a man who police say punched another man in the head last month causing him fatal injuries.

Felix Hopkins, 27, is charged in the Dec. 14 death of Aaron Lang, 39. Hopkins, who was arrested Jan. 10, refused to talk to investigators. Both men are from Oakland.

Lang suffered his injuries Dec. 8 when he was punched in the head during a fight with Hopkins near the intersection of East 15th Street and 23rd Avenue. He died Dec. 14 at Highland Hospital.

Officer Leo Sanchez said Tuesday that the two men were acquaintances who had been feuding for some unknown reason for at least a month. There had been one prior physical altercation between them, police said.

After he was hit Lang fell to the pavement where he struck his head, police said. It was not established whether the punch killed him or the fall to the pavement. The death was classified as Oakland's 123rd homicide of 2012.

Police were able to identify Hopkins as the suspect through witnesses, Sanchez said.