Detective Frederick McLean of the Special Service Squad was the first African American to receive the Department's Medal of Honor. On April 7, 1952, Detective McLean was on a day off when he heard that a robbery was being planned by two men he knew to be armed and dangerous. Driving through Roxbury in his own vehicle, Detective McLean observed one man acting as a lookout in front of a store on Tremont Street, with a second man inside holding the owner at gunpoint. Detective McLean arrested the lookout and used him as a shield as he entered the store to arrest the robber, who had escaped from the state hospital for the criminally insane.
Detective McLean's identical twin brother Francis McLean was also a Boston Police Officer, and the two patrolled Roxbury for many years.