Who is Anthony Mirra from Donnie Brasco and what is their importance?

Anthony Mirra is a "made guy" in the Bonanno family. He brings Pistone into the mafia world and introduces him to Lefty. Much later, Mirra tries to take Pistone from Sonny and Lefty, claiming that he brought him in, and thus, was entitled to his service. Mirra is killed when Pistone's true identity is revealed.