Stefan Mueller was the real name of the villain played by Jack Cassidy in the 1976 Columbo episode, "Now You See Him...". Mueller was a former SS officer who became a popular stage magician named "The Great Santini," and he murders a blackmailing club owner to protect his secret. Columbo exposes him by revealing a flaw in his elaborate illusion and a fatal mistake with a typewriter ribbon that incriminated him.