Mr District Attorney on www.radiothen.network

Mr. District Attorney is a radio crime drama, produced by Samuel Bischoff, which aired on NBC and ABC from April 3, 1939, to June 13, 1952 (and in transcribed syndication through 1953). The series focused on a crusading D.A., initially known only as "Mister District Attorney," or "Chief", and was later translated to television. On television the D.A. had a name, Paul Garrett, and the radio version picked up this name in the final years when David Brian [photo] played the role. A key figure in the dramas was the D.A.'s secretary, Edith Miller (Vicki Vola).

  WIKIPEDIA