One important step in digesting the Connecticut school shooting tragedy could be to draw lessons that might prevent the next one. But that probably won't be easy.
Pinpointing someone who is likely to commit violence is a tricky proposition, according to Dr. Andrew Harper, medical director of the UT-Harris County Psychiatric Center.
"Each individual (shooter) probably has very different circumstances," said Harper. "And there are not that many of them, thankfully, to put together a reliable profile."
While many people make threats, Harper said, very few actually carry them out. And it's almost impossible to predict which individuals will act on their plans.