Inspector James 'Jim' Belden
George Murphy
Professor Albert Kafer
Finlay Currie
FBI Agent Charlie Reynolds
Karl Weber
Michael Dorndoff aka Frank Torrance
Michael Garrett
Anna Kafer
Lotte Palfi Andor
Robert Martin
Ernest Graves
Boldany
Robert Carroll
August Helmuth
Wolfgang Zilzer
Harry Mason
Bradford Hatton
Mrs. Martin
Rosemary Pettit
Landlady
Eva Condon
Samson
Steve Mitchell
Millie / Teresa Zalenko
Virginia Gilmore
John Farrell
Nancy Hale
Westbrook Van Voorhis
Mary Young
Alexi Laschenkov / Gregory Anders
Karl Stepanek
Mrs. Elaine Wilben
Louisa Horton
Chris Zalenko / Gino
Peter Capell
Luther Danzig
Bruno Wick
Mrs. Rita Foss
Vilma Kurer
Philadelphia Suspect
Ann Thomas
Nicholas Wilben
George Roy Hill
Director
Alfred L. Werker
Writer
J. Edgar Hoover
Story
Leo Rosten
Screenplay
Producer
Louis De Rochemont
Original Music Composer
Louis Applebaum
Director of Photography
Joseph C. Brun
Editor
Angelo Ross
Camera Operator
George Stoetzel
Art Direction
Herbert Andrews
Sound
Lodge Cunningham
Assistant Editor
Peter Ratkevich
Unit Manager
Thomas Whitesell
Casting Director
Shirlee Weingarten
Music Director
Jack Shaindlin
Associate Producer
Borden Mace
Lothar Wolff
Edward Horton