21st Precinct was a dramatic police radio drama set in New York City focused on the happenings in an actual police precinct. The show aimed to immerse the listener in the drama, following events from the opening phone call to the final report. The primary character was the Captain of the precinct, who also acted as the show's narrator.

The show aired on the CBS network from July 7th, 1953 through November 1st, 1956. It was presented with the official cooperation of the Patrolmen's Benevolent Association, an organization of more than 20,000 members of the New York City Police Department. Three actors played the role of the Captain: Everett Sloane as Frank Kennelly for the first 109 episodes, James Gregory as Vincent Cronin for episodes 109-144, and Les Damon as Thomas Keough from episode 145 till the end of the series. In total, 92 episodes are in circulation today.

Sources: archive.org, wikipedia.org, otrcat.com