And as police begin to piece together a picture of the gunman, Adam Lanza, they will also be looking at possible motives. Here in the studio with me is NPR science correspondent Shankar Vedantam.
And, Shankar, you have reported in the past about building profiles of these kinds of assailants. I mean, usually, we're talking about men. We're talking about often about white men. Does what we know about Lanza fit that profile of a mass shooter?
This morning in Newtown, state police have briefed residents and reporters on the latest information about yesterday's tragic events. And at the moment, information about the shooter, who's been identified by law enforcement officials as 20-year-old Adam Lanza, is scant. He was found dead at the elementary school. Lanza is believed to have acted alone. NPR's Joel Rose is at this morning's briefing in Newtown. Joel, thanks for being with us.