Analyzing Lanza's DNA: What Made Newtown Shooter Snap?
Description:Geneticists have joined the investigation into the Sandy Hook Elementary School massacre.
The state medical examiner was asked to do a complete analysis of shooter Adam Lanza’s DNA, but they aren’t looking for anything specific.
Geneticists say there are genetic components to mental illness, but there are many genes involved — not just a single gene or mutation.(0:23)