The medical examiner says a man killed by a gunman at a University of Pittsburgh psychiatric clinic was a
25-year-old staff member.

Michael Schaab's  mother tells The Associated Press he worked in the geriatric unit at the clinic and was recently engaged. Mary Schaab says she has no reason to believe he knew the shooter, who was apparently shot dead by campus police and remains unidentified.

She says the family watched Thursday's news coverage of the shootings for hours without realizing her son had been killed. They assumed he was safe because he worked on an upper floor, not near the first floor lobby where the unidentified gunman shot seven people. Another was injured, but not by gunfire.

Schaab says a state trooper arrived to tell her that her son was killed late Thursday night. She says her only other child, Nancy Schaab, was slain at age 26 during a domestic dispute in October 2010.

The other victims are all expected to survive.

(Copyright 2012 by The Associated Press.  All Rights Reserved.)