Police have arrested a suspect in the assault and robbery of an 81-year-old professor in his Temple University campus office Tuesday.
Forty-five-year-old Daryl Moon was arrested Thursday.
He is facing charges in the attack inside Anderson Hall on the north Philadelphia university's campus.
Police said they identified Moon as the suspect through video surveillance outside the building.
The elderly professor was punched in the face multiple times and held at knifepoint. He was hospitalized in stable condition with cuts and bruises as well as swelling and bleeding on the brain.