Boston Blackie is a fictional character created by author Jack Boyle (October 19, 1881 – October 1928). Blackie, a jewel thief and safecracker in Boyle's stories, became a detective in adaptations for films, radio and television—an "enemy to those who make him an enemy, friend to those who have no friend."
Actor Chester Morris was the best-known Blackie, playing the character in 14 Columbia Pictures films (1941–1949) and in a 1944 NBC radio series. Boston Blackie is the role for which Morris is best remembered.
Source
The Jonathan Diamond aka: Rockwell Diamond (Aired June 23, 1944)
The Boston Blackie radio series, also starring Morris, began June 23, 1944, on NBC as a summer replacement for The Amos 'n' Andy Show. Sponsored by Rinso, the series continued until September 15 of that year. Unlike the concurrent films, Blackie had a steady romantic interest in the radio show: Lesley Woods appeared as Blackie's girlfriend Mary Wesley. Harlow Wilcox was the show's announcer. On April 11, 1945, Richard Kollmar took over the title role in a radio series syndicated by Frederic W. Ziv to Mutual and other network outlets. Over 200 episodes of this series were produced between 1944 and October 25, 1950. Other sponsors included Lifebuoy Soap, Champagne Velvet beer, and R&H beer.
THIS EPISODE:
June 23, 1944. "The Jonathan Diamond aka: Rockwell Diamond" - NBC network. Sponsored by: Rinso, Lifebuoy Soap. 10:00 P. M. The first show of the series. Blackie is arrested in Chicago. He's accused of taking $10,000 from a woman's grandfather. It's all the woman's plan to help her recover, "The Jonathan Diamond." The same script was subsequently used on "Boston Blackie" on August 27, 1946. Chester Morris, Harlow Wilcox (announcer), Richard Lane, Charles Cornell (organist), Jan Miner. 29:32. Episode Notes From The Radio Gold Index.
Source