Const. David Chipperfield testified he did not know Boyd had been disarmed. (CBC)

A Vancouver police officer who repeatedly fired at a man and killed him with a shot to the head nearly five years ago will not be charged.

Police Complaint Commissioner Stan Lowe said Monday that extensive investigations have not produced any evidence to suggest Const. Lee Chipperfield used unnecessary or excessive force in handling the incident.

Chipperfield was among several officers who responded to a 911 call about a man's erratic behaviour on the night of August 13, 2007.

He fired multiple shots at Paul Boyd, who was mentally ill and swinging a bicycle chain.

A coroner's inquest in 2010 heard Chipperfield shot Boyd eight times and fired the final shot, which hit the illustrator's head -- even after his partner told him to hold fire and disarmed the man.

Chipperfield testified he believed Boyd was still armed.

The officer said he fired a shot at Boyd's head when he failed to see any blood from the previous shots and thought Boyd was wearing body armour.

Boyd's father has claimed his son was on his hands and knees when he was shot.

Paul Boyd was mentally ill and on his hands and knees when he was shot, his father has claimed. ((Courtesy of the Boyd family))

David Eby, executive director of the B.C. Civil Liberties Association, is hoping the province's new independent investigation office will provide some accountability for officers shooting every bullet in their handguns.

Eby questioned why it took five years to conclude the case and the Office of the Police Complaint Commissioner's use of psychologist who said in a report that Chipperfield's emotional reaction to the events and a restricted focus rendered him "inattentionally" blind.

"The only result of this five-year-long investigation is ever more tortured explanations for an officer's actions in shooting a disarmed and badly injured man in the head."