He killed himself at the library during the incident, police said.  Austin and University of Texas police were searching Tooley's home in south Austin, CNN affiliate KXAN reported.  Police were checking campus buildings for possible explosives left behind, said Austin Police Chief Art Acevedo.  Authorities said earlier they were searching for a possible second suspect, but Robert Dahlstrom, chief of staff in the Austin Police Depart, said they now do not believe there is one.  "A suspected shooter in PCL library is dead," said an alert posted on the university's emergency website at 10:30 a.m. "If you are off campus, STAY AWAY. If you are on campus, lock doors, do not leave your building. All organized classes for today, September 28, are canceled."  The campus had been on lockdown since an alert went out, but spokeswoman Rhonda Weldon said students were allowed to leave, and shuttle buses were to transport students and staff away from the campus. The university canceled all classes for the day.  An ambulance was seen just before 9 a.m. in front of the Perry-Castaneda library, CNN affiliate KXAN reported. SWAT teams, armored vehicles and helicopters surrounded the campus.  "I extend my sympathy to the family, friends, and classmates of the young student who took his life," said university President Bill Powers, who thanked police for their response to the emergency. "In the days ahead we will attempt to understand his actions and to learn from this tragedy."  University of Texas professor Randall Wilhite heard gunshots on his way to class and saw students scrambling to safety. He said he saw a man in a dark suit and a ski mask pulled over his face running toward the direction of the library a little after 8 a.m.  Wilhite said the man was carrying what appeared to be an assault rifle and fired it randomly.
A 19-year-old mathematics major from Austin, Texas, was identified Tuesday as the suspected gunman who fired shots from an AK-47 and then turned the gun on himself, the University of Texas at Austin