Norman A. Carter Jr. was sitting in an Army barracks in the 1960s when he decided to become a police officer--and in 1967, he was accepted into the Philadelphia, Pennsylvania, police academy.

His wife and family did not like the idea of him becoming an officer of the law. Police officers were known as people not to be trusted, and the people in Carter's neighborhood saw them as corrupt and brutal.

But Carter was convinced that the best way to change that perception and help the country heal during the turbulent Civil Rights Movement was to get a badge. He knew that once he...