John Edgar Hoover
Helen Gandy
Clyde Tolson
Charles Lindbergh
Robert Irwin
Anna Marie Hoover
Mitchell Palmer
Dwight Eisenhower
Colonel Schwarzkopf
Palmer's Daughter
Walter Lyle
Agent Smith
Emma Goldman
Albert Osborne
Lela Rogers
Bruno Hauptmann
Edgar's Niece
Anita Colby
Roosevelt's Secretary
Shirley Temple
Bombing Witness
FBI Agent
Robert Kennedy
Raymond Caffrey
Young Boy
Agent Sisk
Prosecutor Wilentz
Palmer's Wife
Inspector
Franklin Roosevelt
Head Secretary
Edgar's Father
Hoover as a Child
Caminetti
Bureau Agent (1919)
Agent Stokes
Inspector Schell
Secret Service Officer
Harlan Fiske Stone
John Condon
Young Agent
Restaurant Host
Arthur Koehler
Attorney General
Senator Friendly
Senator McKellar
Fred Hunter
William Mahan
Stork Club Band
Agent One
Baker's Wife
Bronx Baker
African American Woman (as Shannon McClain)
Lindbergh Nanny (uncredited)
Starlet (uncredited)
Lucille Ball (uncredited)
Gangster's Moll (uncredited)
Secretary (uncredited)
Self (archive footage) (uncredited)
Hollywood Starlet (uncredited)
Racetrack Gambler (uncredited)
Agent Garrison
Edgar's Mother's Doctor
Radical Citizen (uncredited)
Agent Williams
Lawrence Richey