The Killer That Stalked New York (also known as Frightened City ) is a 1950 American film noir directed by Earl McEvoy and starring Evelyn Keyes , Charles Korvin and William Bishop . The film, shot on location and in a semi-documentary style, is about diamond smugglers who unknowingly start a smallpox outbreak in the New York City of 1947. It is based on the real threat of a smallpox epidemic in the city , as described in a story taken from a 1948 Cosmopolitan magazine article.