Trivia

William Powell's last appearance as Philo Vance.

Although they share no scenes, William Powell and Asta appear in this picture, more than a year before The Thin Man (1934) series began.

Dr. Doremus' repeated line "I'm a doctor not a . . . " was later used as the catchphrase of DeForest Kelley's character Dr. Leonard "Bones" McCoy on Star Trek (1966).

All the dialog and plot elements involving the two murdered men, including their names, were used again seven years later in Calling Philo Vance (1940), in which James Stephenson plays Philo Vance. In both movies, the dialog in the scenes pertaining to the murders and the investigation is exactly the same, which indicates that the script from this film was adapted to the story for the latter film, which focuses on the theft of secret aircraft plans. However, in this film, the plot pertains to stolen Chinese art objects.

The miniature buildings Vance uses to illustrate his theory are the actual miniatures used earlier in the picture.