Frank Garland's impressive collection of Impressionist art actually was loaned to the film by collector Edward G. Robinson. Included are works by Gaugin, Degas, Duran, and Robinson's wife, Gladys Lloyd. The collective value of the paintings at the time was estimated to be $213,000 ($2.44M in 2023) for insurance purposes.
In the scene where Edward G. Robinson's character enters the office of DA Ralph Ford (Edward Platt) you can see the Maltese Falcon from John Huston's 1941 film on the barrister's bookcase near the entrance door.
The main character is very loosely based on Bill "The Great Mouthpiece" Fallon, one of the great criminal defense attorneys of the 1920s, who successfully defended gambler Arnold Rothstein in the Black Sox fix of the 1919 World Series.
This film is a remake of 1940's L'homme qui parlait trop (1940) which is, in turn, a remake of The Mouthpiece (1932).