Early Sunday morning at 1:30 am, Soldotna Dispatch was notified by officials at the Spring Creek Correctional Facility in Seward of an assault that occurred between two inmates there.
The man, identified as 29-year-old Elihu Gillespie, was found unresponsive in his cell in the high security area of the prison.
Gillespie was transported from the prison to the Providence Seward Medical and Care Center. He was pronounced deceased at the center at 2:32 am Sunday morning.
The case is under investigation by the Soldotna Alaska Bureau of Investigations. The case has been ruled a homicide.
Gillespie was serving a 50-year sentence for the second-degree murder in the shooting deaths of Christon Lee and Matthew Peterson in 2009.
Next of kin has been notified.