A former mafia hitman has been sentenced for the prison killing of crime boss James “Whitey” Bulger.Fotios “Freddy” Geas appeared in court on Friday after making a deal with prosecutors to change his plea to guilty regarding his role in the murder of Bulger.Geas was sentenced to 25 years in prison for the killing, according to the Associated Press. He is already serving a separate life sentence for his role in multiple other violent crimes.INMATES ACCUSED OF KILLING WHITEY BULGER IN PRISON AGREE TO PLEA DEALS: 3 FACTS FROM GANGSTER’S FBI FILES Fotios “Freddy” Geas appears for a court proceeding in his defense in the Al Bruno murder case, in Springfield, Massachusetts. Geas is being sentenced this week for his role in the killing of Boston crime boss James “Whitey” Bulger. (Don Treeger/The Republican via AP)Bulger, 89, was killed in 2018 after arriving at U.S. Penitentiary, Hazelton in West Virginia.The Irish gangster, who held high-ranking positions in the Boston mob during the 1970s and 1980s, is believed to have been marked for murder when he became an FBI informant against a rival gang. The crime boss consistently denied working with the federal agency.Bulger was serving two life sentences after being convicted of numerous criminal acts in 2013 — including the killing of 11 people.3 INMATES CHARGED IN PRIOSN KILLING OF BOSTON GANGSTER JAMES ‘WHITEY’ BULGER SET FOR PLEA HEARING, SENTENCING James “Whitey” Bulger is pictured in a mugshot in 2011. (Bureau of Prisons/Getty Images)Prosecutors claim Geas beat Bulger to death with a metal lock attached to a belt just hours after the crime boss arrived in West Virginia following a transfer from a Florida prison.Geas is connected to the Genovese crime family of New York City but is not a “made member” — likely due to his lack of Italian ancestry.Another mobster tied to the murder, Paul DeCologero, pleaded guilty to assault charges last year and was sentenced to four years imprisonment — a small penalty compared to the life sentence he is already serving for the attempted murder of a teenage girl.A third individual linked to Bulger’s death, Sean McKinnon, pleaded guilty to lying to FBI agents after prosecutors claimed he served as lookout during the murder. CLICK HERE TO GET THE FOX NEWS APP This undated booking photograph shows Fotios “Freddy” Geas. The mafia-affilitated hitman pleaded guilty to his role in Bulger’s murder in a West Virginia prison in 2018. McKinnon had already spent 22 months in prison following his indictment and was not sentenced to any additional time. He was transported back to Florida where he could continue a supervised release.Bulger’s family previously sued the FBI over what they claim was negligence by putting the targeted crime boss among the general prison population instead of a more secure location.The lawsuit was ultimately dismissed by a judge in January 2022. Timothy Nerozzi is a writer for Fox News Digital. You can follow him on Twitter @timothynerozzi and can email him at [email protected]