In France, the title was changed to "Menaces sur la ville", or roughly "Threat Over the City" so the citizens would not be confused, as the country was wild about the sport of tennis at the time.
Walter Abel had a resemblance to the real-life New York City District Attorney Thomas E. Dewey. So when his character Hugh Allison references his successful prosecution of "Lucky Lugano" (referring to Lucky Luciano), audiences of the time would not have missed the connection with Dewey.
The car the gangsters drive in from their meeting to the produce market near the beginning of the picture is a 1938 Buick Limited Touring Sedan.
Denny's new truck is a 1937 GMC F-Series.