The killers generally felt tense before they acted but at peace and in control during the rampage. Some committed suicide when they were done. But a surprising number just gave up. They’d made the statement they wanted to make and hadn’t thought about what came after.

The crucial point is that the dynamics are internal, not external. These killers are primarily the product of psychological derangements, not sociological ones.

Yet, after every rampage, there are always people who want to use these events to indict whatever they don’t like about society. A few years ago, some writers tried to blame violent video games for a rash of killings. The problem is that rampage murderers tend to be older than regular murderers and they tend not to be heavy video game users. Besides, there’s very little evidence that violent video games lead to real life violence in the first place.

These days, people are trying to use the Aurora killings as a pretext to criticize America’s gun culture or to call for stricter gun control laws. (This doesn’t happen after European or Asian spree killings.) Personally, I’ve supported tighter gun control laws. But it’s not clear that those laws improve public safety. Researchers reviewing the gun control literature for the Centers for Disease Control and Prevention, for example, were unable to show the laws are effective.

And gun control laws are probably even less germane in these cases. Rampage killers tend to be meticulous planners. If they can’t find an easy way to get a new gun, they’ll surely find a way to get one of the 200 million guns that already exist in this country. Or they’ll use a bomb or find another way.

Looking at guns, looking at video games — that’s starting from the wrong perspective. People who commit spree killings are usually suffering from severe mental disorders. The response, and the way to prevent future episodes, has to start with psychiatry, too.

The best way to prevent killing sprees is with relationships — when one person notices that a relative or neighbor is going off the rails and gets that person treatment before the barbarism takes control. But there also has to be a more aggressive system of treatment options, especially for men in their 20s. The truly disturbed have always been with us, but their outbursts are now taking more malevolent forms.