The film was made by British International Pictures. It was originally to be released under the same title as the novel, "Enter Sir John", but this was changed to the simpler "Murder!" during shooting. A number of changes were made from the book, including altering the names of the two principal characters. The portrayal of the character Sir John Mernier was loosely based on that of the actor Gerald du Maurier, who was a friend of Hitchcock. Hitchcock later adapted three novels written by du Maurier's daughter Daphne du Maurier: "Jamaica Inn" (1939), "Rebecca" (1940) and "The Birds" (1963). Hitchcock makes his cameo appearance in the film as a man walking past the murder victim's house.