Known as the underboss of the Gambino crime family. He helped bring down John Gotti, the boss of the family, by becoming a witness for the Federal Bureau of Investigation.
When he was 13 years old, he joined a street gang known as the Rampers in Bensonhurst, Brooklyn.
He published a book called Underboss in 1997 about his experiences with John Gotti and their trial.
He was youngest of three children born to parents Giorlando (Gerry) and Caterina (Kay) Gravano.
He was known for taking down fellow mafioso John Gotti.