I am looking for the name of a movie set in Los Angeles or San Francisco from the 1940's or 1950's. I don't remember the actors. The premise is that a member of Scotland Yard comes to the U.S. to track a mad killer who escaped the U.K. As it turns, out the member of Scotland Yard is actually the escaped killer. I remember a person goes missing and they find the body in the closet or wall panel of an office. Any help would be appreciated. Thank you for the responses in advance.