who is sammy
Salvatore Sammy the Bull Gravano (born March 12, 1945) is a former underboss of the Gambino crime family. He was well known as John Gotti's underboss and right-hand man from 1986-1992. is known as the man who helped bring down John Gotti, the family's boss, by agreeing to become a Federal Bureau of Investigation (FBI) government witness.