Patrolman George C. Kimball was the first Detroit police officer killed in the line of duty on October 5, 1883. According to the Officer Down Memorial Web page, 245 Detroit officers have died in the line of duty, 160 from gunfire. The others died from knifings, assaults, accidental gunshots, vehicle crashes and a variety of natural causes such as heart attacks.
Source : “Kimball was first Detroit police officer to die on patrol”, Detroit Free Press, July 17, 2022.