Rondo Hatton
— Hal Moffet AKA 'The Creeper'
Tom Neal
— Clifford Scott
Jan Wiley
— Virginia Rogers Scott
Jane Adams
— Helen Paige
Donald MacBride
— Police Captain M. J. Donelly
Peter Whitney
— Police Lieutenant Gates
Fred Coby
— Young Hal Moffet
Janelle Johnson Dolenz
— Joan Bemis (as JaNelle Johnson)
Mary Ann Bricker
— Mary Ann Obringer (uncredited)
Tristram Coffin
— Police Lieutenant / voice of radio announcer (uncredited)
Joseph Crehan
— Police Commissioner Salisbury (uncredited)
John Hamilton
— Professor Cushman (uncredited)
Frank O'Connor
— Policeman at Helen's Apartment (uncredited)
Beatrice Roberts
— Nurse (uncredited)
Charles Wagenheim
— Pawnbroker (uncredited)
William Ruhl
— Policeman at Helen's Apartment (uncredited)
James Nolan
— Police Dispatcher (uncredited)
Oscar O'Shea
— Mr. Haskins - Grocer (uncredited)
Patrick McVey
— Detective at Helen's Apartment (uncredited)
Warren Jackson
— Jeweler (uncredited)