GREENSBURG (AP) — A Pennsylvania man has been charged with homicide in the death of his 92-year-old father.

State police initially charged 40-year-old Douglas Novak with arson related to the December 20 fire in Hempfield Township, about 30 miles east of Pittsburgh.

WTAE-TV reports that state police upgraded charges Monday after Novak told investigators he had beaten his father, Frank Novak, over several hours before setting the fire.

Police say Novak attacked the World War II veteran because he believed his father had taken or hidden his cellphone.

Novak was arraigned on the new charge Monday and is currently in custody.

According to the initial complaint, Douglas Novak told police that he intentionally lit the fires and fled as firefighters arrived.

A message left for Novak’s attorney was not immediately returned.