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.