As he wrapped up his term as the head of British Columbia’s police watchdog, the Independent Investigations Office, Richard Rosenthal delivered a parting blow.

A former Los Angeles prosecutor and head of police oversight agencies in Denver and Portland, Mr. Rosenthal used his final report to take to task officers who pull the trigger and then refuse to write down their accounts.

“With great power comes great responsibility,” he said in an interview with The Globe and Mail. “And one of those responsibilities is you account for your actions when you kill somebody under your authority as a police officer. You have a responsibility to do so.”