PITTSBURGH — State police have charged an inmate at a northwestern Pennsylvania county jail with criminal homicide for allegedly “pile-driving” a guard on his head during an altercation last month.

Twenty-four-year-old Gregory Brown was arraigned on the charge Tuesday afternoon and is jailed without bond.

Crawford County District Attorney Francis Schultz said Brown was in the county lockup when he attacked 49-year-old Gary Chapin on Oct. 13. Schultz said Brown was upset that he could not get a pencil sharpened quickly enough, calling the killing “quite awful” and “ridiculous.”

Brown’s public defender didn’t immediately return a call.

Chapin died Monday of complications from head injuries he suffered in the attack.