According to a book on movie makeup, this is the first known film use of contact lenses to change the color of an actor's eyes.
The last of six films in which Robert Young and Florence Rice were paired as a romantic team. Their first film together as such was Sworn Enemy (1936).
The character of Michael Morgan seems to be loosely based on Houdini, who created illusions for his own magic act (Morgan merely sells them to others) and made a life-long dedication to exposing fake psychics and mediums.
Frank Sully is listed in studio records as the bus driver, but he was replaced by Matt McHugh. A modern source lists Fred Warren as police surgeon, but the role of the coroner (the only surgeon in the movie) was played by E. Alyn Warren.