Mr. District Attorney is a radio crime drama series that focuses on the adventures of a dedicated district attorney, initially known as "Mister District Attorney" or "Chief." The show is known for its meticulous and accurate representation of the realities of the crime world. This can be attributed to the show's creator, former law student Ed Byron, who went to great lengths to study crime statistics, criminology texts, and even mingle with criminals and police officers to create realistic storylines. The show emphasized the importance of the district attorney's role in safeguarding citizens' fundamental rights, acting as a champion of the people, defender of truth, and guardian of life, liberty, and the pursuit of happiness.

The show aired on NBC and ABC from April 3, 1939 to June 13, 1952, and in transcribed syndication through 1953. Throughout its run, various actors played the title role, including Dwight Weist, Raymond Edward Johnson, Jay Jostyn, and David Brian. The show also featured a voice known as the "Voice of the Law," which defined the duties and responsibilities of the district attorney. There were 195 known episodes of Mr. District Attorney during its time on air, and the show experienced remarkable ratings success, rivalling the likes of Jack Benny and Bob Hope. The show's striking similarity to real-life crime events even caught the attention of the FBI, who paid a visit to Byron in response to one of the storylines mirroring an actual criminal case.

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