The Whistler - 48/05/19 (ep316) Murder on Margin

The Whistler is an American radio mystery drama which ran from May 16, 1942, until September 22, 1955, on the west-coast regional CBS radio network. The show was also broadcast in Chicago and over Armed Forces Radio.

On the west coast, it was sponsored by the Signal Oil Company: "That whistle is your signal for the Signal Oil program, The Whistler." There were also two short-lived attempts to form east-coast broadcast spurs: July 3 to September 25, 1946, sponsored by the Campbell Soup Company; and March 26, 1947, to September 29, 1948, sponsored by Household Finance. The program was also adapted into a film noir series by Columbia Pictures in 1944.
Characters and story
I...am the Whistler, and I know many things, for I walk by night. I know many strange tales, many secrets hidden in the hearts of men and women who have stepped into the shadows. Yes... I know the nameless terrors of which they dare not speak!

Each episode of The Whistler began with the sound of footsteps and a person whistling. (The Saint radio series with Vincent Price used a similar opening.) The haunting signature theme tune was composed by Wilbur Hatch and featured Dorothy Roberts whistling with an orchestra.
A character known only as the Whistler was the host and narrator of the tales, which focused on crime and fate. He often commented directly upon the action in the manner of a Greek chorus, taunting the characters, guilty or innocent, from an omniscient perspective. The stories followed a formula in which a person's criminal acts were typically revealed either by an overlooked but important detail or by the criminal's own stupidity. An ironic ending, often grim, was a key feature of each episode. But on rare occasions, such as "Christmas Bonus" broadcast on Christmas Day 1944, the plot's twist of fate caused the story to end happily for the protagonist.

Bill Forman, a veteran radio announcer, had the title role of the Whistler for the longest period. Others who portrayed the Whistler at various times were Gale Gordon, Joseph Kearns, Marvin Miller (announcer for the show, who occasionally filled in for Forman and played supporting roles), and Bill Johnstone (who had the title role on radio's The Shadow from 1938 to 1943). Cast members included Betty Lou Gerson, Hans Conried, Joseph Kearns, Cathy Lewis, Elliott Lewis, Gerald Mohr, Lurene Tuttle and Jack Webb.
Writer-producer J. Donald Wilson established the tone of the show during its first two years, and he was followed in 1944 by producer-director George Allen. Other directors included Sterling Tracy and Sherman Marks with final scripts by Joel Malone and Harold Swanton. Of the 692 episodes, over 200 no longer exist. In 1946, a local Chicago version of The Whistler with local actors (including Everett Clarke as the Whistler) aired Sundays on WBBM, sponsored by Meister Brau beer.