Due to permit restrictions, the film makers were unable to use replica guns on the movie. Toy "cap" guns were used instead.
The original script featured both "Mr. Blue" and "Mr. Brown" but their parts were written out after the actors who were meant to play them failed to show.
Martin Lewis was cast as "Nice Guy Eddie" after the original choice for the role, Gary Delaney, was unable to make the shoot. He later provided the voice over.