Lettieri would go on to act with some of Hollywood's biggest screen names, including Steve McQueen in The Getaway, Charles Bronson in Mr. Majestyk, John Wayne in McQ, Richard Harris in The Deadly Trackers, and Marlon Brando and Al Pacino in The Godfather. Lettieri co-wrote the screenplay for the 1971 gangster movie Villain, which starred Richard Burton and Ian McShane.