Even though it's stated in the ending narration that former Capone lieutenant Luigi Renaldo was sentenced to prison and was sent to Alcatraz, this would not have been the case in real life as the government took special care to send convicted associates of Capone to other Federal prisons besides Alcatraz and earlier Atlanta.
Narrator: Norbert was a man with a genius for figures in his head. He was known among his associates as a man who never made mistakes. But he made one...he tried to quit.
Norbert: Mr. Renaldo's always treated me fairly.
Ness: How? By sending someone to beat you up?
Norbert: You think they would hurt my family
Ness: Mr. Norbert, Luigi Renaldo knows that inside your head is enough information to blow him into Alcatraz.
Norbert: My little girl needs me.
Ness: Of course she needs you but she needs you alive.
Narrator: Luigi would have been out in twelve years except for a slight mishap. He died in 1939 at Alcatraz.