LA BELLE, Pa. (AP) – An inmate serving time at a Pennsylvania prison for murder has been charged with criminal homicide after police say he punched another inmate, causing fatal injuries.

Police say 51-year-old John Steckley was found unresponsive in his cell at the State Correctional Institution-Fayette a day after he was assaulted by 31-year-old Daysean Wykee Brock. Steckley was taken to a Pittsburgh hospital, where he died June 19, 2016. A coroner said he died of blunt impact to the head.

A witness told police Brock blindsided Steckley, who hit his head on the ground as he fell.

Brock is serving time for a third-degree murder in Philadelphia in 2012. He has denied involvement in Steckley’s death.

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