"Blackie is the natural suspect when an expensive pearl necklace is stolen while he is supposed to be guarding it."
Chester Morris
as Horatio 'Boston Blackie' Black
June Vincent
as Doris Howell
Richard Lane
as Insp. William R. Farraday
Patricia Barry
as Joan Howell (as Patricia White)
George E. Stone
as The Runt
Frank Sully
as Sgt. Matthews
Edward Norris
as Igor Borio
Fay Baker
as Margie O'Reilly, alias Sandra Doray
William Forrest
as Mason Carter
Sarah Selby
as Claire Carter
Mary Currier
as Helen Kenyon
Bess Flowers
as Party guest
Rudolph C. Flothow
Producer
Edward Bock
Story
Charles R. Marion
Dwight Caldwell
Editor
Seymour Friedman
Director
Maurice Tombragel
Screenplay
Louis Diage
Set Decoration
Jack Boyle
Characters
George Brooks
Art Direction
Mischa Bakaleinikoff
Music Director
Philip Tannura
Director of Photography