The state's attorney general office was investigating an off-duty police officer's fatal shooting of a man who apparently attacked him during a case of road rage early Monday, reports the Associated Press.

The New York Police Department officer was driving his personal vehicle in the East New York neighborhood of Brooklyn shortly after midnight when he was involved in a traffic dispute with 37-year-old Delrawn Small, police said.

When the officer and Small stopped at a red light, Small got out of his vehicle and punched the officer repeatedly in the head through an open window, according to police. The officer, who had just finished his shift and was on his way home, pulled out his service weapon and killed Small, authorities said. The officer, whose name wasn't immediately released, was treated at a hospital for minor injuries.

Small's family held a news conference later Monday demanding a full investigation.