Although based on a true story, Sir Alfred Hitchcock deliberately left out some of the information that pointed to Manny's innocence, to heighten the tension.
This movie is one of Martin Scorsese's favorite Sir Alfred Hitchcock movies, and was an influence on Taxi Driver (1976).
On the DVD, the running commentary revealed that when the crew went to film the scenes at the country hotel, Sir Alfred Hitchcock stayed in his limo due to the cold outside and decided to move the production to Hollywood to complete the movie.
Manny Balestrero earned $22,000 from the film, which went to pay loans needed for Rose's care. The amount equates to $247,000 in 2023.
Alfred Hitchcock: Narrating the prologue. This was the only time that he spoke in any of his movies.
Alfred Hitchcock: Hitchcock filmed one of his usual cameos, standing in a restaurant as Manny sits, but decided on using a narrated prologue instead, believing the levity of a cameo worked against the serious tone of the film.