Black Mass (2015)

Based on the true story of James "Whitey" Bulger, an Irish Mob godfather and a FBI informant who had a "secret trading" deal with his brother William "Billy" Bulger, a state senator and Boston public figure, and John Connolly, an FBI agent. They planned to take down the Italian Mafia in Boston, which went awry and things turned massively violent. When the credence in each other began fading out, drug dealing, murders, and extortion rose, forcing the FBI's Boston office to confirm that Whitey Bulger was one of the most notorious criminals in US history and also one of the FBI's Ten Most Wanted List criminals.