Salvatore "Sammy the Bull" Gravano (born March 12, 1945) became an Underboss of the Gambino crime family after teaming up with John Gotti in planning and executing the murder of Paul Castellano, the then-Gambino boss. After Castellano's murder, Gotti moved into the top position and Gravano moved in as his Underboss.
In 1991, a F.B.I. investigation led to the arrest of several key players in the Gambino family including Gotti and Gravano. Looking at a long prison sentence, Gravano became a government witness in exchange for a lighter sentence. His testimony against Gotti, which included admitting to their taking part in 19 murders, resulted in a conviction and life sentence for John Gotti.
His nickname "Sammy the Bull" quickly changed to "King Rat" among his peers after his testimony. For awhile he was in the U.S. protection program, but left it in 1995.
See Also: Glossary of Common Mafia Terms
