Three men, including a Mafia hitman, were charged in the beating death of notorious Boston crime boss James “Whitey” Bulger in a West Virginia prison, the Justice Department announced Thursday.

Fotios "Freddy" Geas, 55, Paul "Pauly" DeCologero, 48, and Sean McKinnon, 36, were charged with conspiracy to commit first degree murder.

Geas and DeCologero are accused of striking Bulger in the head multiple times and causing his death in October 2018 while they were incarcerated at U.S. Penitentiary Hazleton in Bruceton Mills, West Virginia. In addition to the conspiracy charge, Geas and DeCologero were charged with aiding and abetting first degree murder, along with assault resulting in serious bodily injury.

Geas faces a separate charge for murder by a federal inmate serving a life sentence and McKinnon faces another charge of making false statements to a federal agent.