The mind of a rampage killer can live behind the face of the boy next door. Can science shed any light in these darkest of dark places? There is not much data to go on. From Columbine through Newtown, in most cases, the shooter ends up dead, either by his own hand or by police.

But Andy Williams is one of the few living school rampage shooters.

See the story here:  http://www.pbs.org/newshour/bb/science/jan-june13/afternewtown_02-20.html