Corrected entry: Vermin tells his sidekick that he plans to kill Tommy Kelly at the exact moment that Cagney is killed in the movie. But there's no way for him to have known anything about what happened in the movie, because no one had even seen it yet. Even though the specific movie is never named, the radio announcement Vermin had listened to the previous day clearly states that DA Kelly and the governer would be attending the premiere of Cagney's new movie.
Corrected entry: In one of the scenes at Johnny's pet shop, a shot out the window shows a passerby on the sidewalk answering a cellular telephone. The movie takes place in the 1940's.