 Gotti's underboss Salvatore "Sammy the Bull" Gravano aided the FBI in finally convicting Gotti.In 1991, Gravano agreed to turn state's evidence and testify for the prosecution against Gotti after hearing the boss making several disparaging remarks about Gravano on a wiretap that implicated them both in several murders.In 1992, Gotti was convicted of five murders, conspiracy to commit murder, racketeering, obstruction of justice, tax evasion, illegal gambling, extortion, and loansharking.