CHICAGO -- People who commit violent acts tend to fall into at least one of several categories. Young adults are more prone to violence, as are people of lower social class, IQ and education level. Individuals exhibiting violent behavior are 10 times more likely to be male. Mental illness, particularly paranoid delusions, is a major factor. But a history of violence is the best predictor of future violence.
Unfortunately, given the people who populate college campuses, most of those risk factors are present in enough people that the criteria aren't much help for college officials trying to determine whether students or employees might become the next college shooter.
"Even when we're trained, even when we work in the field, even when we know what we're looking for, it's very difficult to do," Susan Kimmel, an assistant professor of psychiatry at Case Western Reserve University, said here Friday at the annual convention  of the American College Health Association. "If we look at our general risk factors for general violence, they probably don't work as well in this particular population that we're trying to find."
Not to mention that proactive profiling -- assuming that a person will commit violence based on their characteristics -- hasn't been proven to work anyway. But despite a largely discouraging (or as she put it, "depressing") presentation on what, if anything, we can learn about best future practice based on past shooters, Kimmel did have one piece of encouragement: she suggested the people in the room were on the right track.
"Threat assessment teams are really the best thing you can do -- we don't have anything better," Kimmel said, referring to the strategy that proliferated throughout colleges after Seung-Hui Cho executed the most devastating campus massacre in history, killing 33 people including himself at Virginia Tech a little more than five years ago.
The composition of threat assessment or behavioral intervention teams varies by campus, but tend to bring together staff from different departments -- police, student affairs, counseling and psychology, for instance -- to monitor and evaluate potentially at-risk students.
But health officials at the presentation also noted the pitfalls of over-reliance on threat assessment teams.
"I know too many campuses that focus their teams on students of concern, and they don't have mechanisms for people who have been removed," one person said. (While 57 percent of shooters from 1990 to 2008 were graduate students -- likely dealing with work, financial or family pressures that undergraduates aren't -- 21 percent were "other": staff or former students who came back.) "The truth is, they're an increased risk for coming back and doing targeted campus violence."
In fact, that was the case with a number of shooters Kimmel profiled in her presentation. Peter Odighizuwa, who killed two professors and a student at Appalachian School of Law in January 2002, was no longer enrolled at the time, although accounts differ on whether he'd been removed or withdrawn voluntarily. Two years earlier, James Easton Kelly had murdered his adviser and himself after academic struggles led to his being dropped from the graduate English program at the University of Arkansas, where he had been enrolled for a decade. At Kimmel's own institution, in May 2003, 90 people were trapped hostage in a campus building for an entire day as former graduate student Biswanath Halder roamed the halls with a gun, killing a graduate student and injuring two others. (And though he didn't return to campus, Jared Lee Loughner, who shot Congresswoman Gabrielle Giffords and six other people in 2010 in Tucson, Ariz., had been asked to leave  Pima Community College.)
It's not exactly a coincidence that all those shootings were relatively recent: as Kimmel showed, they're becoming more frequent. There were three in the 1960s, when sniper Charles Whitman killed 18 and wounded 31 others from atop the clock tower at the University of Texas at Austin. There were two each in the 1970s and '80s, before an uptick to four in the 1990s and then a couple dozen in the 2000s. In this decade, there have already been four. (Noting that access to and history with firearms is a risk factor for violence as well, Kimmel made a sobering prediction: with more people coming out of the military and going to college, she said, "we actually might see a little more of this.")
Yet the movement to allow guns on campuses has never been stronger , and Kimmel acknowledged that the pro-concealed carry movement has the momentum right now. Several states already leave it up to campuses to decide whether to allow concealed carry, and some courts in the past couple of years have struck down institutional attempts to ban them. At least 14 other states have pending legislation that would allow guns on campuses.
Kimmel rejected the claim often made by concealed carry advocacy groups that campus bans do nothing to deter shootings and may actually permit them by preventing law-abiding students and staff with weapons permits from being able to potentially stop a shooter with their own guns. Shootings frequently occur in states banning concealed carry; advocates often point, for example, to Utah, which has never had a campus shooting and yet is the only state to explicitly prohibit colleges from banning concealed carry.
But that's not because of the law, Kimmel said.
"We have more shootings in areas where we have more schools," she said. "I would hypothesize that if we allow more guns on college campuses, we are going to have more trouble, and I think that just goes without saying."
In the meantime, Kimmel said, the best thing colleges can do is continue working on threat assessment -- and don't hesitate to hospitalize a student involuntarily if he or she is thought to pose a danger. If there is true reason to believe a student is a risk to others, she said, but the student later sues for breach of confidentiality under FERPA, the courts will likely side with the institution.
"We're always in a balance between our professional liability and doing what's in the best interests of the patient," Kimmel said. "You've got to focus on treatment and not the legal aspects.... Community safety, on a college campus, has got to be your top priority."