He rarely spoke and even gave a school presentation entirely by computer, never uttering a word.
He liked tinkering with computers and other gadgets, and seemed to enjoy playing a violent video game, choosing a military-style assault rifle as one of his weapons.
New details about Adam Lanza emerged Friday, as the nation paused to mark one week since he slaughtered 20 first-graders and six adults at Sandy Hook Elementary School in Newtown.
Multiple funerals and visitations were held Friday, and at the hour of the attack, 9:30 a.m., a bell tolled 26 times, once for each victim killed at the school.
Lanza also fatally shot his mother before blasting his way into Sandy Hook, and killed himself after the school massacre.