The Unknown Why in the Aurora Killings YOU'VE had 48 hours to reflect on the ghastly shooting in Colorado at a movie theater. You've been bombarded with "facts" and opinions about James Holmes's motives. You have probably expressed your opinion on why he did it. You are probably wrong. I learned that the hard way. In 1999 I lived in Denver and was part of the first wave of reporters to descend on Columbine High School the afternoon it was attacked. I ran with the journalistic pack that created the myths we are still living with. We created those myths for one reason: we were trying to answer the burning question of why, and we were trying to answer it way too soon. I spent 10 years studying Columbine, and we all know what happened there, right? Two outcast loners exacted revenge against the jocks for relentlessly bullying them. Not one bit of that turned out to be true. But the news media jumped to all those conclusions in the first 24 hours, so they are accepted by many people today as fact. The real story is a lot more disturbing. And instructive. At every high school, college and school-safety conference I speak at, I hold up the journals left behind by the killers, Eric Harris and Dylan Klebold. The audience is shocked at what they learn. Perpetrators of mass murder are usually nothing like our conceptions of them. They are nothing like a vision of pure evil. They are complicated. Mr. Harris kept a sort of journal for an entire year, focused largely on his plan to blow up his school and mow down survivors with high-powered rifles. Mr. Klebold kept a more traditional journal for two years, spewing a wild array of contradictory teen angst and deep depression, grappling seriously with suicide from the very first page. Audiences are never surprised by the journal of Mr. Harris. It's hate-hate-hate all the way through. He was a coldblooded psychopath, in the clinical use of that term. He had no empathy, no regard for human suffering or even human life. Mr. Klebold's journal is the revelation. Ten pages are consumed with drawings of giant fluffy hearts. Some fill entire pages, others dance about in happy clusters, with "I LOVE YOU" stenciled across. He was ferociously angry. He had one primary target for his anger. Not jocks, but himself. What a loathsome creature he found himself. No friends, no love, not a soul who cared about him or what became of his miserable life. None of that is objectively true. But that's what he saw. It's a common high school malady, taken to extremes. Psychologists have a simple term for this state: depression. That surprises a lot of people. Depressives look sad, but that is the view from the outside. Of course they're sad; they've probably gone their entire day getting berated relentlessly, by the single person in the world whose opinion they hold most dear - themselves. Psychologists describe depression as anger turned inward. When that anger is somehow turned around, and projected outward, watch out. Dylan Klebold was an extreme and rare case. A vast majority of depressives are a danger only to themselves. But it is equally true that of the tiny fraction of people who commit mass murder, most are not psychopaths like Eric Harris or deeply mentally ill like Seung-Hui Cho at Virginia Tech. Far more often, they are suicidal and deeply depressed. The Secret Service's landmark study of school shooters in 2002 determined that 78 percent of those shooters had experienced suicidal thoughts or attempts before mass murder. At this very moment, the police have probably gathered a great deal of evidence from James Holmes. They may well have a clear read on his motives right now. It is vital that they share this information fully with the public, but just as vital that they conceal much or all of it while they conduct their investigation. Testimony from friends, family and survivors of the massacre is also crucial, and witnesses are highly suggestible. Information must be withheld in the short run to safeguard corrupting their stories. Not for seven years, as in the case of the Columbine diaries, but perhaps several weeks. Over the next several days, you will be hit with all sorts of evidence fragments suggesting one motive or another. Don't believe any one detail. Mr. Holmes has already been described as a loner. Proceed with caution on that. Nearly every shooter gets tagged with that label, because the public is convinced that that's the profile, and people barely acquainted with the gunman parrot it back to every journalist they encounter. The Secret Service report determined that it's usually not true. Resist the temptation to extrapolate details prematurely into a whole. Every time you begin to think we're ready to answer the burning why, focus on the image of Dylan's hearts. The killer is rarely who he seems. Dave Cullen is the author of "Columbine," who is now at work on a book about gay soldiers.