James "Whitey" Bulger was moved from a prison in Florida to a facility in Oklahoma, the United States Bureau of Prisons said on their website.
No reason was given for the move, or where he will be transferred to from the Oklahoma City Federal Transfer Center.
Bulger was convicted by a federal jury in Boston in 2013 for participating in 11 murders in the 1970's and 1980's, and was sentenced to life in prison.
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The 89-year-old was transferred to the United States Penitentiary Coleman II in Sumterville, Florida in 2014 from a prison in Arizona.