The electrician turns on the basement electricity and says, "That's 30 for tonight." Since the days of telegraphs the number '30' has been used by journalists to let the copy editors and type setters know where the end of an article is. Over time, '30' came to denote any conclusion or completion.
Two of the book titles that detective Donald MacBride reads out loud are "Murder in the Laundry" and "Murder in the Chop Suey Restaurant," a clear reference to Sidney Toler's alter ego, Charlie Chan.
In one scene, Brian Aherne takes a burning roast out of an oven. The music Werner R. Heymann composed for this scene was used many years later for You Bet Your Life (1950) as the theme played whenever the wheel of fortune is being spun by a contestant.
The Greenwich Village basement apartment set also appears in My Sister Eileen (1942), made a few months earlier. That movie also shared several cast members, including star Brian Aherne.
Story based on the third novel in the Jeff & Haila Troy Mystery series: The Frightened Stiff (1942) by Audrey Roos. The second novel in the series If the Shroud Fits (1941) was filmed as Dangerous Blondes (1943); with the characters names changed to Barry and Jane Craig and being played by Allyn Joslyn and Evelyn Keyes. The following year, Joslyn and Keyes made a film considered an unofficial sequel: Strange Affair (1944). It is not based on Roos's story but features a comic strip artist and his wife who investigate a murder.