Law enforcement authorities are increasingly advising school officials - and even young students - to physically confront suspects in future campus attacks as a final line of defense. "These incidents are becoming a fact of life," University of Wisconsin-Madison Police Chief Susan Riseling told a [PERF] meeting of law enforcement colleagues in Washington. "If there is no other option, take the shooter out." Prof. Pete Blair of Texas State University said that in many cases, potential victims "have no choice" but to defend themselves. In a study of 84 active shooter incidents between 2000 and 2012, Blair said that in 16 incidents, victims stopped the attack before police arrived, either by subduing the attacker - 13 cases - or shooting the attacker in three cases.