A Batman logo is shown at the memorial to victims...

A Batman logo is shown at the memorial to victims of the Aurora, Colo., movie theater shooting (July 27, 2012). Credit: AP

With 12 dead and 58 injured, the July 20 massacre at the midnight premiere of "The Dark Knight Rises" in Aurora, Colo., is one of the largest mass shootings in U.S. history. Aurora is only 20 miles from Columbine High School, where seniors Eric Harris and Dylan Klebold killed 13 and injured 24 in 1999. We may think we know what makes the perpetrators of mass shootings -- mostly boys and men -- tick. Though psychology doesn't always lend itself to hard statistics, there are some patterns that might surprise you.

1. Shooters are insane.

The 2002 Safe School Initiative report, by the Secret Service and the Department of Education, looked at 41 attackers across 37 incidents from 1974 to 2000. It concluded that only 17 percent "had been diagnosed with mental health or behavior disorder prior to the attack." Most had never had a mental health evaluation. However, 78 percent "exhibited a history of suicide attempts or suicidal thoughts." Adult and teen shooters do not suddenly snap. Their anger and planning often develop over time. And the more they plan, the more an argument can be made, in the eyes of the law, that they are sane.

Indeed, mental illness is not automatically an excuse, legally speaking. Charges against James Holmes, the Colorado theater shooting suspect, are to be filed Monday. Whether he could invoke an insanity defense will hinge on whether it can be proved that he had a mental condition that rendered him unable to distinguish right from wrong. In other words, if Holmes says he carried out the shootings because aliens were guiding him, he might be deemed insane.

By contrast, most experts (after his death) have declared Columbine shooter Eric Harris a psychopath. With that label, he could not have pleaded insanity because, while he would be seen as coldblooded, he would also be considered rational, calculating and aware of his actions.

Mass murderers may have various diagnoses (the other Columbine shooter has been called a depressive), but they are usually seen as being fueled by anger and vengeance.

2. Cutting down on illegal gun sales would help.

Not necessarily. The Safe School Initiative found that 68 percent of the attackers obtained guns from their homes or those of relatives. Case in point: Jonesboro, Ark., middle school shooters Mitchell Johnson, 13, and Andrew Golden, 11, took guns from the homes of Golden's parents and grandparents.

A friend of the Columbine shooters purchased at a gun show three of the four weapons they used and passed them on to the killers without breaking any laws. Holmes legally obtained four firearms from local gun stores, according to various news accounts. Many shooters do not have the type of criminal record, such as a felony conviction, that would prohibit them from legally obtaining guns.

3. A shooter's loved ones should have seen it coming.

Teenagers, including those who commit mass shootings, often hide things from their parents. In the case of Columbine, the vast writings and videos left behind by the 17- and 18-year-old killers do not indicate that anyone knew of their plans, and there was no criminal prosecution to that effect. Civil suits accusing the killers' parents of not stopping the shootings were settled, although their depositions have been sealed for years to come.

While young shooters may not leak information to a parent, they may drop hints to others. The Safe School Initiative found that in 81 percent of the cases studied, "at least one person had information that the attacker was thinking about or planning the school attack.

"Almost always -- 93 percent of the time -- that person was "a peer, a friend, schoolmate or sibling." Many shooters do not have a history of violent crime that might help predict such an incident. Still, a heightened awareness may be the ripest area for preventing mass shootings: Small but troubling hints could be an indication that a bigger problem is brewing.

Sometimes, though, these warning signs go completely unnoticed. According to news reports, Holmes mailed a University of Colorado psychiatrist a journal with details and drawings of how he was going to commit a massacre. The package arrived July 12 but hadn't been opened before the shooting, according to one report. The university says it got the package the Monday after the shootings.

4. Communities come together after mass shootings.

They do but often only temporarily. I reported from the Columbine and Aurora shootings from the first hours and through the first days (and 13 years and counting in the case of Columbine). I also traveled to Virginia Tech in 2007 days after the shooting on that campus.

More than $4.6 million in donations was raised for Columbine victims, but distributing it brought gut-wrenching questions and debates over how much to give to the families of those who died versus the injured.

Lawsuits, which usually follow mass shootings, also foster acrimony within the community. According to a study of the 1997 West Paducah, Ky., school shooting, suits were filed against students who had heard that something was going to happen and even against producers of the movie "The Basketball Diaries," which the shooter reportedly watched. The victims' families who brought the suits said acquaintances shunned them, they received hate mail and they were accused of wanting only money and stalling the healing process.

And soon after the Aurora shootings, another hyper-partisan debate on gun control began.

There is a sense of unity after mass shootings. But the threads begin to quickly unravel.

5. It can happen anywhere.

Yes, but mass shootings at schools tend to occur in suburbs and small towns, where high school is the main driver of social status. Students who feel like outsiders have few, if any, other places to turn for friends and self-esteem.

School shootings also tend to occur in the South and the West, where researchers have identified a "culture of honor," in which people place a high value on their reputation and, in some cases, are willing to fiercely defend it to the point of violence. This culture comes from long-standing regional traditions that combine chivalry with the need to defend one's property in places where law enforcement was sparse.

It has been translated to the schoolyard by shooters who retaliate with violence when they feel they have lost their status. A 2009 study by researchers at the University of Oklahoma found that states with a culture of honor had more than twice as many school shootings per capita as other states. Mapping just some locales shows the pattern: Bethel, Alaska; Springfield, Ore.; Littleton, Colo.; Pearl, Miss.; and West Paducah.

Similar issues of vengeance for a wrong, or a perceived wrong, committeed by individuals or society are also typical with adult shooters.

Writer Jeff Kass, a former reporter for the Rocky Mountain News, is the author of "Columbine: A True Crime Story." He wrote this for The Washington Post.


Unlimited Digital AccessOnly 25¢for 5 months