NORRISTOWN, Pa. (AP) — Authorities say an eastern Pennsylvania prison inmate is facing first- and third-degree murder charges following the death of his cellmate following an alleged assault.

Thirty-eight-year-old Joseph Hodum was charged with attempted murder after the March 30 attack on 50-year-old Stephen Klampfer as the two shared a cell in the Montgomery County Correctional Facility infirmary.

County prosecutors say the charges were upgraded following the April 13 death of the victim, who was in a medically induced coma on life support but died without ever regaining consciousness.

Authorities allege that Hodum repeatedly punched the victim in the head, even when he went to the floor, and then stomped on his head more than 20 times until correctional officers intervened.

Hodum’s attorney declined to comment Saturday, saying he hadn’t yet spoken with his client.