Police in Philadelphia say they don't yet know why a retired Villanova University professor was fatally stabbed in her apartment.
University officials on Tuesday confirmed the death of Carol Ambruster, a former assistant professor of astronomy and astrophysics.
Police say the 69-year-old educator was killed Monday in her apartment in the Germantown section of the city. No arrests have been made.
A spokesman for the private Catholic university says Ambruster taught there from 1987 until her retirement two years ago.
Villanova spokesman Jonathan Gust says the school is saddened to learn of her death.
The university's campus is about 12 miles northwest of Philadelphia.