It used to be that a shocking act of gun violence would invariably elicit a chorus of demands for tighter gun control laws. How things have changed. Now an episode like that invariably elicits a chorus of demands for tighter gun control laws and a chorus of demands for looser gun control laws. What the reactions demonstrate is that no matter what happens, people are very good at finding confirmation for what they already think.
In this case, the first error is taking a freakishly horrible event as a basis for anything except mourning. The carnage at Virginia Tech was as bad as gun crimes get, but it was also as rare as they get.
Seeing mass slaughter on a campus makes all of us feel at risk. But that's because we are focusing on the unusual and ignoring the usual. All the less dramatic facts indicate that deadly violence is a diminishing danger.
Nationally, your chance of being a murder victim has plunged by 44 percent since 1991. University students, as a rule, have even less cause for worry. All the colleges in the country have some 17 million students, but in an average year, they suffer fewer than 20 on-campus homicides.
In the aftermath of the killing spree in Blacksburg, the Violence Policy Center rushed to ascribe it to "the easy access to increasingly lethal firearms that make most killings possible." But when auto fatalities occur, we don't take them as evidence of the need to cut down on the number of people allowed to drive, or on the horsepower of cars.
Guns, like many inventions, are potent tools that have valuable as well as destructive uses. Lately, though, they are being used less and less for bad purposes. The number of gun murders has dropped by 38 percent since 1993, and the rate of nonfatal gun crimes is one-third what it was then.
These weapons are not getting more lethal but less -- because an increasing proportion are handguns, which are typically not as powerful as rifles and shotguns. In this case, the shooter used one of the least deadly firearms in existence, a .22-caliber pistol. If someone wanted to shoot you and let you decide what weapon he would use, it would be your choice.
Cho Seung-Hui's other pistol was a 9mm, an established weapon that is far from being the most powerful handgun around. "Increasingly lethal firearms" had nothing to do with this crime.
Some people who think the law should allow the carrying of concealed handguns (which I favor) make the mistake of seeing them as a cure-all. Virginia law allows licensed gun owners to carry weapons, but not on public university campuses. The thinking is that if students and faculty had the freedom to pack heat, someone could have stopped Cho in the act -- or deterred him from even trying.
But would that have saved anyone? I put the question to Florida State University criminologist Gary Kleck, who is revered by gun rights supporters for his work on the defensive value of guns. He agrees that an armed student or professor could well have succeeded in stopping the slaughter, but doubts one would have been present.
"Most people wouldn't carry a gun to a classroom in daytime, because college campuses are very safe," he says. "It's a hassle to carry a gun. It's heavy, it's dangerous, it scares other people, and it puts weird bulges in your clothing."
Nor is there any assurance that someone with a handgun would have been able to act effectively -- something far easier in theory than in practice. Even police often miss their targets. And it's hard to deter a killer who is seeking his own death, as Cho was.
All this says nothing about the effect on learning from lots of people sitting in classrooms with lethal ordnance at hand. You don't have to be a gun control fanatic to recognize that putting firearms into a seminar room might cramp the discussion. To think guns belong in every setting is to make a sensible insight -- that they can be useful for self-defense -- into a fetish.
It may seem obvious that when an atrocity is committed with a gun, we should respond by revising our gun laws. In fact, what we know suggests that if there is a way to prevent mass killings, it will have to be found someplace else.