Investigators, searching for motive, scrambled to learn more about 20-year-old gunman Adam Lanza, who killed himself after massacring 26 -- including 20 children -- at a Connecticut elementary School on Friday morning.
Richard Novia was the school district's head of security until 2008 and served as adviser for the school technology club that Adam and his older brother belonged to. The group offered students a chance to work on computers, videotape school events and produce public-access broadcasts.
Novia says Lanza clearly "had some disabilities."
He told The Associated Press that if Lanza had burned himself, he would not have felt it physically. He remembered that the boy sometimes had "an episode" and completely withdrew from whatever was happening around him.
An official said Lanza had Asperger's syndrome, but experts say there's no connection between the disorder and violent behavior. Asperger's is a mild form of autism often characterized by social awkwardness.
A law enforcement official says Adam Lanza had been diagnosed with Asperger's. The official spoke on condition of anonymity because the person was not authorized to discuss the unfolding investigation.
Columbus, Ohio, psychologist Eric Butter says research suggests people with autism have a higher rate of aggressive behavior than the general population. He says this includes outbursts, shoving or angry shouting, but typically does not include planned, intentional violence.
High school classmates say Lanza was bright but painfully shy, anxious and a loner. Butter says those characteristics are consistent with Asperger's.
"We would hang out, and he was a good kid. He was smart," Lanza's former classmate Joshua Milas said. "He was probably one of the smartest kids I know. He was probably a genius."
Friday's massacre has elicited horror and soul-searching around the world.
Gov. Dannel P. Malloy says the "innocent little boys and girls" were "taken from their families far too soon."
Investigators have questioned the gunman's older brother, who's not believed to have been involved in the rampage at Sandy Hook Elementary in prosperous Newtown, 60 miles northeast of New York City.