I knew one of my colleagues at AOL had attended Virginia Tech; he was still in school when he started working for my group as an intern. I work remotely, though, and hadn't heard how affected by yesterday's tragedy he was. Today at our early morning meeting I heard a little more; he'd known one of the first people killed. He knew the killer. And then, an hour ago, he published this astonishing piece on how he'd immediately thought of Cho, whose 'macabre' offerings in a play writing class prompted his fellow students to recoil.

Naturally, after a tragedy like this (or even, yesterday, while it was still unfolding), everyone asks: "what should we have done differently?" Late at night, when BBC is on the local public radio station, all the talk was of gun control. When I woke up and NPR had taken over, the conversation had changed. I wondered yesterday about whether this would lead to heightened security on college campuses everywhere, and this morning a U.S. security expert was talking about how better training (read: heightened security) can lead to prevention of tragedies like this. He said that he personally has averted more than a dozen mass shootings simply by knowing how to look for individuals who are carrying weapons; they walk and act differently when they're packing a loaded gun.

But there's something else, and while I'd like to get all nature/nurture and blame his parents (if you look at the plays he wrote, you'll see exactly why I write that), it's a little more practical. It's about being more watchful, both at companies where rogue employees have been known to come in and gun down their former co-workers, and at public schools, and at all the other places where people become close enough to know one another and (subsequently) develop the passion required to murder those close acquaintances. It's about being attentive -- not just to whether someone's packing heat but whether or not they're capable of doing so. I don't have an answer to "what should we do when we discover the guy in the next cube is a psychopath?" -- but I think it's an easier question than "how do we regulate guns so only the good guys have access?"