IF YOU WANT A SENSE OF JUST HOW terrible Monday's crimes were, here's something to try: imagine yourself committing them. It's easy enough to contemplate what it would feel like to rob a bank or steal a car; you might even summon a hint of the outlaw frisson that could make such crimes seem appealing. But picture yourself as Cho Seung-Hui, the 23-year-old student responsible for the Virginia Tech bloodbath, walking the halls of the school, selecting lives to extinguish and then ... extinguishing them. It is perhaps a measure of our humanity that we could sooner imagine ourselves as the killed than as the killer, and find it easier to conjure up what it would feel like to plead for our lives than to take someone else's.
That is where the hard work of trying to make sense of a crime like that at Virginia Tech always hits a wall. We can debate, as we predictably do in these cases, what an incident like this means for our endless national argument about guns and violence and the coarsening of the culture. That's well-mapped ground. What remains uncharted is the unlit places in the minds of the people who are capable of doing these things--and, by extension, in all our minds. What is it that makes individual members of a usually empathetic species turn rogue? How does one of our most primal faculties--the ability to understand that things that cause me pain or fear would do the same to you and that I therefore ought not do them--get so completely shut down? Is empathy optional, at least in some people, and if so, how does that emotional decoupling take place? More important, if we can figure out that part of the question, can we figure out how to prevent such things from happening? "We always ask ourselves, 'Is this a person who has no conscience at all?'" says Stanton Samenow, a forensic psychologist and author of the 2004 book Inside the Criminal Mind. "They seem to have an unfathomable ability to shut off knowledge of the consequences, of the difference between right and wrong. It's critical for us to try to understand that worldview and mental makeup."
For all the ink and airtime that follow an attack like the one at Virginia Tech, mass murder is an exceedingly rare crime. The rate of killings in the U.S. involving five or more victims--one generally accepted definition of a mass killing--represented less than 1% of all homicides 25 years ago, and still does today. Among kids, the overall violence figures are actually plummeting, with the number of children under 17 who commit murder falling 65% between 1993 and 2004. Mass killing, says Diane Follingstad, a professor of clinical and forensic psychology at the University of South Carolina, "is a low-rate-base thing. It just does not happen very often."
When it does happen, the people likeliest to commit the crime fall into a drearily predictable group. They're 95% male, and 98% are black or white--not a big surprise since more than 87% of the population is made up of those two races. Cho, a native of South Korea, is a rare exception. If the killers' profiles are all more or less the same, however, their crimes aren't. The best known--or at least most lurid--of the mass killers are the Ted Bundys and Jeffrey Dahmers, the serial murderers whose crimes often play out over decades. In most cases, people who commit such murders are driven by a dark, even sexual pleasure, and while remorse is often associated with the acts--which accounts for the long lapses that can occur between them--those tuggings of conscience are quickly overcome by the impulse to kill again. "There is a charge and a thrill associated with the murders," says Samenow.
That does not seem to be the case with a mass murderer who kills at once. Few people who are in a position to observe a Dahmer at work survive to talk about it, but plenty of people present at shootings like those at Virginia Tech or Columbine High School in Littleton, Colo., in 1999 make it out alive. And what they describe about the killer's mien as the shooting is taking place sounds nothing like a person who's thrilled by--or even much enjoying--what he's doing. There is, survivors report, a cold joylessness to the proceedings, something that in its own way is a lot harder to parse than the perverse pleasure of a serial killer.
What makes mass murderers do it? Trying to find the much-looked-for snapping moment--the one inciting incident that pushes a killer over the edge--rarely gets you very far. Cho's lethal outburst, by all accounts, may have been simmering for months, if not years. In 2005, after Cho sent harassing messages to two female students, a Virginia court ruled him a danger to himself and others. His package of angry, self-pitying videos, stills and text, sent to NBC News on the day of the killings, probably took days to prepare.
"Snapping is a misnomer," says Dr. Michael Welner, associate professor of psychiatry at New York University School of Medicine. "These people plan to carry out a mass killing without any indication of when they will do it. Instead of snapping, imagine a cage that someone has the capacity to unhinge. They simply decide that today is the day."
Mass murder, in short, is not a random act. There are things that explain it. Psychosis, for one, can never be ruled out. Russell Weston, a 41-year-old killer who went on a shooting spree in the Capitol Building in Washington in 1998, was a paranoid schizophrenic. Brain injury in an otherwise healthy person can lead to similar violence. Damage to the frontal region of the brain, which regulates what psychologists call the observing ego, or the limbic region, which controls violence, reflection and defensive behavior, can shut down internal governors and trigger all manner of unregulated behavior. "Somebody who had damage to both regions would be a bad player for sure," says forensic psychiatrist Neil Kaye, a faculty member at Jefferson Medical College in Philadelphia.
From everything we know so far, however, Cho was suffering from none of these things. Any wounds that he carried were deeper, psychic ones--and in all likelihood, he shared them with most of the mass shooters who have gone before him.