- Country: USA
- Genres: Drama, Mystery
- Release: 1931-12-12
- Director: Thornton Freeland
- Writers: Sam Spewack
- Language: English
- Stars: Una Merkel , William Collier Jr. (1902–1987) , Zasu Pitts , Purnell Pratt (1885–1941) , Ralf Harolde , Clyde Cook , June Clyde , Nat Pendleton (1895–1967) , Clarence Muse , Hooper Atchley
- Runtime: 66 min
- Awards: N/A
- AKA: The Secret Witness (United Kingdom) , The Secret Witness , The Secret Witness (United States of America) , Terror by Night (United States of America) , Penthouse Murder (United States of America) , A Testemunha Invisível (Brazil)
- Plot: A wealthy, cheating husband is found murdered in his penthouse apartment. The police soon arrest a suspect, but the victim's downstairs neighbor believes the man is innocent and sets out to prove who really committed the murder.
- IMDB:tt0022358
The Secret Witness Cast · · · ALL
Thornton Freeland
Director
Una Merkel
Lois Martin
Purnell Pratt
(1885–1941)
Capt. McGowan
Zasu Pitts
Bella
Clarence Muse
Jeff - Building Janitor
Paul Hurst
Officer Brannigan
Ralf Harolde
Lewis Leroy
William Collier Jr.
(1902–1987)
Arthur Jones aka Casey
Nat Pendleton
(1895–1967)
Gunner - Bodyguard
Rita La Roy
Sylvia Folsom
Hooper Atchley
Herbert 'Bert' Folsom
James Durkin
Detective
Mike Donlin
Mike - Speakeasy Proprietor
June Clyde
Tess Jones
Clyde Cook
Larson - Building Engineer
Greta Granstedt
Gunner's Woman Friend
Henry Hall
Police Commissioner Martin
Maston Williams
Contact Detective
Billy Bletcher
Radio Announcer's Voice