In 1945, Dick Powell portrayed Phillip Marlowe in the movie "Murder My Sweet" based on Raymond Chandler's novel "Farewell My Lovely". This was a radical departure in character for Mr. Powell from a Hollywood song and dance man to a hard-boiled detective. On June 11,1945, Lux Radio Theatre brought "Murder My Sweet" to radio, again with Dick Powell in the lead. These two performances prompted his selection for the part of Richard Rogue, in Rogue's Gallery after his role for Lux Radio Theatre and Richard Diamond came four years later.

Richard Diamond, Private Detective came to NBC in 1949. Diamond was a slick, sophisticated detective, with a sharp tongue for folks who needed it. Diamond enjoyed the detective life, but not as much as entertaining his girl, Helen Asher. After each show, he would croon a number to his Park Avenue sweetheart. Mr. Powell, a former song and dance man, was perfect for the role. He added an extra dimension to the 40's hokey private eye drama.

Diamond was a rough gumshoe that would often get knocked on the head with a revolver butt or other items. His counterpart on the police force was Lt. Levinson who often accepted Diamond's help reluctantly. Levinson would claim to get stomach trouble whenever Diamond would call him and would take bicarbonate to settle his aching stomach. Although they always seem at odds with each other, Diamond and Levinson were best friends.