Gary Pavela, director of student judicial programs at the University Maryland at College Park, is an expert on how colleges can assist troubled students. In a forthcoming installment of his weekly newsletter on campus law and policy, the "Synfax Weekly Report," Mr. Pavela discusses Monday's shootings at Virginia Tech. Among other observations, he says administrators' ability to identify violent offenders is limited. "We're pretty good at predicting how cows will behave," he writes. "But people live in both an idealized world and the physical world around them. The complexity of that mental interaction remains beyond the scope of our best predictive models." In this interview, he discusses how administrators and faculty members are limited in what they can do to help students they're concerned about. He also describes ways of removing a troubled student from a campus.