- Executive Meddling: In the original novel, the Lodger is the Avenger. The studio didn't want the star, Ivor Novello, to play a serial killer and Hitchcock didn't have his Auteur License yet, so they had the ending changed so that the Lodger was innocent. This wasn't too egregious, since it fits the common Hitchcockian theme of a man being falsely accused. Still, other adaptations, such as the 1944 version with Laird Creegar, follow the original story to great effect.
- Ripped from the Headlines: Most of the story was inspired by Jack the Ripper.
Trivia / The Lodger