Il signore e la signora Sherlock Holmes

On July 21, 1936, the Los Angeles Evening Citizen News (aka Hollywood Citizen-News) listed RKO films in production or preparation, including "The Riddle of the Dangling Pearl," based on a Stuart Palmer novella. James Gleason and Helen Broderick were indicated as the principal actors. They had appeared in RKO's previous Hildegarde Withers production, Murder on a Bridle Path (1936). However, on Aug. 17, the paper reported that Broderick would not be appearing in the film, as she had too many other assignments. (She appeared in five RKO releases in 1936.) The article indicated that James Gleason's wife Lucille was negotiating to take over the role of Hildegarde Withers, but on Sept. 4 an L.A. Times story indicated that James would be teamed with Zasu Pitts for the film, which was released in December as Il signore e la signora Sherlock Holmes (1936).

The Italian couple that Officer Cassidy talks to near the beginning of the movie say "good night" to him in Spanish.

Followed by Forty Naughty Girls (1937)