Hell in the Heavens

(1934)

Lt. Schroeder (as Rudolph Amendt)

Stamboul Quest

(1934)

Karl (as Rudolph Amendt)

The Fountain

(1934)

Geof Van Leyden

Here's to Romance

(1935)

Violinist

Rendezvous

(1935)

Radio Operator (uncredited)

Last of the Pagans

(1935)

Superintendant's Assistant (uncredited)

We're in the Legion Now

(1936)

Sgt. Groeber

Champagne Waltz

(1937)

Emperor Franz Joseph

That Mothers Might Live

(1938)

Doctor (uncredited)

Confessions of a Nazi Spy

(1939)

Captain Straubel

The Mad Empress

(1939)

Herzfeld

Pack Up Your Troubles

(1939)

Von Richtman

Espionage Agent

(1939)

Paul Strawn (as Robert O. Davis)

Escape to Paradise

(1939)

Alexander Komac

The Mortal Storm

(1940)

Gestapo Official Hartman

Knute Rockne All American

(1940)

Elder in Norway (uncredited)

Arise, My Love

(1940)

Prussian Officer (Uncredited)

The Great Dictator

(1940)

Tomanian Commandant at Osterlich / Robert O. Davis

Meet the Wildcat

(1940)

Feral--Henchman

The Man I Married

(1940)

Storm Trooper

Underground

(1941)

Official

King of the Texas Rangers

(1941)

His Excellency

A Dangerous Game

(1941)

Dr. Fleming

Down in San Diego

(1941)

Henry Schrode

Mr. Dynamite

(1941)

Frederick the Butler

Junior Army

(1942)

Horner - Nazi Saboteur (as Robert O. Davis)

Spy Smasher

(1942)

Col. Von Kohr

The Phantom Plainsmen

(1942)

Colonel Eric Hartwig (as Robert O. Davis)

The Pied Piper

(1942)

Lieutenant

Sherlock Holmes and the Secret Weapon

(1942)

Braun (uncredited)

Eagle Squadron

(1942)

German Squad Leader

The Secret Code

(1942)

Rudi Thysson

The Great Impersonation

(1942)

Karl Hofmann

Desperate Journey

(1942)

Kruse

To Be or Not to Be

(1942)

Gestapo Sergeant at Desk at Top of Hotel Stairs (uncredited)

Riders of the Northland

(1942)

Agent (as Robert O. Davis)

Nazi Agent

(1942)

Cab Driver (uncredited)

The Devil with Hitler

(1942)

Nazi Officer at Hitler's filmed Speech (uncredited)

Counter-Attack

(1945)

Stillman

Escape in the Desert

(1945)

Hoffman

Dangerous Millions

(1946)

Rudolph Busch

Under Nevada Skies

(1946)

Alberti

Act of Violence

(1949)

German (voice) (uncredited)

Kill or Be Killed

(1950)

Gregory Marek

Target Unknown

(1951)

Doctor (uncredited)

Captain Scarface

(1953)

Dr. Yeager

Phantom from Space

(1953)

Dr. Wyatt

South Sea Woman

(1953)

Capt. van Dorck

The Snow Creature

(1954)

Dr. Louis DuPont

Jungle Gents

(1954)

Dr. Goebbel

Magnificent Obsession

(1954)

Dr. Albert Fuss

A Star Is Born

(1954)

Mr. Ettinger (uncredited)

Silver Needle in the Sky

(1954)

Dr. Loran

King Richard and the Crusaders

(1954)

Austrian Knight (uncredited)

Frankenstein 1970

(1958)

Wilhelm Gottfried

She Demons

(1958)

Col. Karl Osler

A Private's Affair

(1959)

Dr. Leyden

On the Double

(1961)

Oberkommandant

The Pigeon That Took Rome

(1962)

Col. Wilhelm Krafft

The Prize

(1963)

Mr. Rolfe Bergh - Chaperon

Decision at Midnight

(1963)

Spy Smasher Returns

(1966)

Col. Von Kahr

Horrible Horror

(1986)

Colonel Karl Osler in 'She Demons'