Surveilling the notorious criminal, Crawford’s FBI colleague is convinced he had “full-blown dementia”.

Crawford, however, is sceptical and suspicious of Capone, proposing it might be an “elaborate act”.

The FBI believe Capone may have hidden a large sum of money, with Hardy’s co-star Matt Dillon as Johnny telling him: “Guys like you don’t just misplace $10 million.”

At one point, Hardy growls: “We made a promise, some day we was gonna make it big.”