Betzner said Temple police and Philadelphia police detectives were investigating whether the attacker was a student or someone who somehow got into the building off the street.
The attacker was described as a black man in his early to mid-20s, about 6 feet tall, wearing a tan shirt and tan slacks.
Students and employees are required to show a Temple ID to enter most buildings on campus, including Anderson Hall.
In the same campus building in November 2007, a 22-year-old graduate student was locking up a classroom for the night when a man who was not a student but still managed to get into the building brutally beat and raped her in a bathroom.
Betzner said that he could not recall a faculty member being attacked before.
"This is extremely unusual," he said. "In my 10 years here, I cannot recall a single case of a faculty member being assaulted, so this is a very, very unusual situation."
An alert was sent to students and faculty members about yesterday's attack around 12:30 p.m., and Betzner said campus police stepped up patrols in the area.
Tipsters should call Temple police at 215-204-1234 or Central Detectives at 215-686-3093.
On Twitter: @morganzalot