Among the many documents and photos Connecticut police recently released in connection with the December 2012 school shooting in Newtown is a photo of the shooter, Adam Lanza, then 20. In it he is just a toddler, and sits surrounded by guns and ammunition, wearing a camouflage hat. He is teething on a pistol.
At one point, everyone was an adorable bundle of joy. What went wrong for these serial killers?