There is a lot of controversy about who pulled triggers in that massacre--but all are agreed that McGurn wasn't one of them. He planned the massacre mainly in revenge for having nearly been killed in a trap laid by Moran's two chief thugs--the Gusenberg brothers. He sold Capone on the idea by convincing him that Moran could be erased in the same hit. To protect himself, McGurn holed up in a hotel with his mistress Louise Rolfe (known as "the blonde alibi"), and kept calling for room service at the time of the shooting to reinforce the alibi.

According to Capone's most recent biographer, Lawrence Bergreen, the shooters were Fred (Killer) Burke, Albert Anselmi, John Scalise and Pasquale (Patsy) Lolordo.

Q. What was the name of the Brooklyn Irish gang that was after young Capone, precipitating his flight to Chicago?