Attorney and "Deadly Sins" host Darren Kavinoky on how T.J. Lane's mental state and rough childhood will be factored into investigation.

Brian Ries, social media editor for Newsweek/Daily Beast, on how students used Twitter during the Chardon school shooting.

Craig Scott, Columbine shooting survivor and founder of "Rachel's Challenge," on similarities to the Chardon school shooting.

Jessie Klein, author of the upcoming book "The Bully Society," on how children are increasingly bullied and isolated.

Virginia Tech survivor Colin Goddard, now with the Brady Campaign to Prevent Gun Violence, on Chardon school shooting.