This was columnist/TV panelist Dorothy Kilgallen's film debut, and only movie as an actress apart from a gag cameo in Pajama Party (1964) 28 years later. Fittingly, she plays a reporter.
Whitman Chambers' novel was first serialized with the title "The Affair of the Green Lantern," but no other details are known
The remote writing machine in MacKelvey's office is a "Telautograph", first patented in 1888 by Elisha Gray (1835-1901), an American electrical engineer. He is most famous for losing credit for inventing the telephone to Alexander Graham Bell. The machine was first shown to the public at the 1893 Chicago World Fair. Another example can be seen in Earth vs. the Flying Saucers (1956).
Three years earlier, Bruce Cabot and Frank Reicher were among the stars of King Kong (1933) in the respective roles of Jack Driscoll and Captain Englehorn, joined here also by three bit players from "Kong"--Lee Phelps, Alexander Pollard and Paddy O'Flynn. Three years after this, both Cabot and Reicher would be castmates for a third and final time in Mystery of the White Room (1939), on that film joined by Helen Mack, the lead actress of Son of Kong (1933) in which she worked with Reicher reprising his Englehorn role. Cabot would work with Mack two more times--in Mickey the Kid (1939) (also with "Kong" actor James Flavin who had played Second Mate Briggs under Cabot's Driscoll character) and Divorce (1945) (with "Kong" extra Jean Fenwick).
Many cast members in studio records/casting call lists did not appear or were not identifiable in the movie. These were (with their character names, if any): Joe Caits (Ambulance Driver), Hal Cooke (Headwaiter), Lester Dorr (Reporter), Kenneth Gibson (Hotel Clerk), John Hansen (Fight Announcer), Richard Kipling (Headwaiter), Frank Reicher (Theo Drukker), Dick Rush (Doorkeeper), Al Williams (Page Boy) and Charles Williams. Additionally, George Meeker was in a Hollywood Reporter production chart, but he was not seen in the movie either.