Federal authorities said three men have been indicted in connection with the beating death of notorious Boston mob boss James “Whitey” Bulger in a West Virginia prison in 2018.

Springfield mobster Fotios “Freddie “ Geas, 55, along with Paul J. DeCologero, 55, and Sean McKinnon, 36, were charged on Wednesday with conspiracy to commit first-degree murder, a spokeswoman for the U.S. Attorney’s office in West Virginia said in a statement issued shortly after 5 p.m. Thursday. All three were imprisoned with Bulger.

Geas and DeCologero are accused of striking Bulger in the head multiple times and causing his death in October 2018 while all were incarcerated at the Hazleton federal prison in Bruceton Mills, W.Va., the spokesowman said.

In addition to the conspiracy charge, Geas and DeCologero have been 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.

McKinnon faces a separate charge of making false statements to a federal agent.

The spokeswoman said Geas is still incarcerated at prison in Hazelton. She said DeCologero is no longer being held at Hazelton but remains housed at an undisclosed location elsewhere in the federal prison system. McKinnon had been released and was Thursday in Florida, she said.

Bulger was 89 years old when he died.