EnglishJames Whitmore as Police Sgt Ben Peterson
Edmund Gwenn as Dr Harold Medford
Joan Weldon as Dr Patricia 'Pat' Medford
James Arness as Robert Graham
Onslow Stevens as Brig Gen Robert O'Brien
Sean McClory as Maj Kibbee
Chris Drake as Trooper Ed Blackburn
Sandy Descher as The Ellinson Girl
Mary Alan Hokanson as Mrs Lodge
Don Shelton as Trooper Capt Fred Edwards
Fess Parker as Alan Crotty
Olin Howland as Jensen
Marshall Bradford as Psychiatrist
Richard Bellis as Mike Lodge
John Beradino as Patrolman Ryan
Robert Berger as Patrolman Sutton
Oscar Blanke as Alcoholic Ward Patient
Willis Bouchey as Official at DC Meeting
Richard Boyer as Trooper
Waldron Boyle as Doctor
Alexander Campbell as Official
James Cardwell as Officer
Royden E Clark as Jeep Driver
John Close as Johnny Police Aircraft Pilot
Booth Colman as Reporter
James Conaty as Washington Official
Robert Scott Correll as Jerry Lodge
Walter Coy as Reporter
Dean Cromer as MP Sergeant
Richard Deacon as Bald reporter Los Angeles news conference
Eddie Dew as Officer
Lawrence Dobkin as Los Angeles City Engineer
Ann Doran as Child Psychiatrist
Wally Duffy as Airman
Cliff Ferre as Cliff Police Lab Man
Norman Field as Gen James
Joseph Forte as Coroner Putnam
Dean Fredericks as Det Curtis
Russell Gaige as Coroner
Otis Garth as Admiral at Second Conference
Dorothy Green as Matron
Mary Lou Holloway as Blonde
Gayle Kellogg as Gunner
Kenner G Kemp as Trooper
Hubie Kerns as Jeep Driver
Warren Mace as Radio Operator
Chad Mallory as Loader
John Maxwell as Dr Grant
Matthew McCue as Gramps Johnson Storekeeper
Charles Meredith as Washington Official
Forbes Murray as Government Official
Leonard Nimoy as Staff Sergeant Telex Operator
Jack Perrin as Army Officer
Charles Perry as Soldier
Grandon Rhodes as Alcoholic Ward Doctor
Joe Sawyer as Capt O'Connell
William Schallert as Ambulance Attendant
Fred Shellac as Attendant
Joel Smith as Smitty Ben's Jeep Driver
KL Smith as Trooper
Douglas Spencer as Reporter
Janet Stewart as WAVE
Victor Sutherland as Senator at DC Meeting
Dub Taylor as Railroad Yard Watchman
Harry Tyler as Harry Alcoholic Ward Patient
Dick Wessel as Railroad Detective
Harry Wilson as Alcoholic Ward Patient