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.
Chanteuse66
22nd Dec 2005
Correction: First, there's no evidence the movie was never seen by anyone. It was merely premiere night. Vermin was already disguised as a theater worker before telling the sidekick his plan, so it's plausible he did at least see part of it to plan his attack.
Bishop73