Mr. Keen, Tracer of Lost Persons
Here is a sample of the online episodes currently available at The Old Time Radio Fan:
Case of Man Who Invented Death
(10.05 MB) [29:16]
Case of Murder With a Thousand Witnesses
(9.84 MB) [28:39]
The Case of the Moonless Night
1944-01-06 (10.35 MB) [30:08]
Yellow Talon Murder Case
1949-09-22 (10.18 MB) [29:40]
Shrieking Prisoner Murder Case [Part 1 of 4] other parts
1954-06-21 (5.08 MB) [14:47]