Malice Aforethought (1931) by Francis Iles
Hitchcock apparently wanted to film an adaptation of the novel with Alec Guinness playing the role of "Dr Bickleigh". It was the opening line of the novel which intrigued Hitchcock the most:
It was not until several weeks after he had decided to murder his wife that Dr. Bickleigh took any active steps in the matter.
Despite not filming the novel, Hitchcock did produce a two unbroadcast radio pilots of the story in the mid-1940s, under the titles Once Upon a Midnight (1947) and The Alfred Hitchcock Show (circa 1947).
A radio adaptation was broadcast in December 1975 by CBS Radio Mystery Theater.