Orson Welles Jonathan Wilk Diane Varsi Ruth Evans Dean Stockwell Judd Steiner Bradford Dillman Arthur A. Straus E.G. Marshall District Attorney Harold Horn Martin Milner Sid Brooks Richard Anderson Max Steiner Robert F. Simon Police Lt. Johnson Robert Burton Charles Straus Wilton Graff Mr. Steiner Louise Lorimer Mrs. Straus aka 'Mumsy' Gavin MacLeod Padua - Horn's Assistant Edward Binns Tom Daly Colin Kenny Courtroom Spectator (uncredited)