Edna May Oliver was forced to take a salary cut, as were other RKO contractees, for austerity reasons when she worked on this film.
In the last scene of Penguin Pool Murder (1932) (the previous film), Inspector Oscar Piper proposes to Hildegarde Withers, and they dash out the door to get a marriage license. However, the two characters are not married in this sequel or the one which follows. In fact, there's no mention of an engagement, and the characters give no indication that they're romantically involved. Inspector Piper in this film even asks on their meeting if she has, sarcastically, ". . . gotten into a mess over some man".
The booklet Detective Sergeant Donahue (Edgar Kennedy) is reading in the hospital bed is The ABC Book of Crocheted Edges and Corners, No. 3. It was the third volume of a series of four 16-page pattern booklets published by Asmus Bradley Co. Inc., Chicago, Illinois between 1923 and 1927.
Edgar Kennedy returns as the slow-thinking Donovan, although he seems to have been promoted to Detective Sergeant. In both films he is knocked unconscious. In Penguin Pool Murder (1932) in a bathroom and here in a cellar. Kennedy's iconic bald pate is visible although in the first film his head was shaved.
Louise Halloran's musical notation on the blackboard shows a C Major scale on the top clef, which Hildegarde vocalizes using D# as the tonic (three semitones sharp). The clef below shows a six-note progression with A and D notes. Hildegarde whistles the progression correctly, albeit one semitone sharp, using A# and D# which are in the same key as the scale.