Production notes

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 film's sets were designed by the art director John Mead. Hitchcock makes his cameo appearance in the film as a man walking past the murder victim's house. 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 two novels and one short story written by du Maurier's daughter Daphne du Maurier: Jamaica Inn (1939), Rebecca (1940) and The Birds (1963). The German language version of the film, Mary (1931), was shot simultaneously on the same set with German-speaking actors. Miles Mander reprised his role as Gordon Druce in Mary, though the character's name was changed to Gordon Moore.