"Have you found his best friend? Have you found a friend?" Novia asked. "You're not going to. He was a loner."
Adam was not physically bullied, although he may have been teased, Novia said.
The club gave the boy a place where he could be more at ease and indulge his interest in computers. His anxieties appeared to ease somewhat, but they never disappeared. When people approached him in the hallways, he would press himself against the wall or walk in a different direction, clutching tight to his black case.
"The behavior would be more like an 8-year-old who refuses to give up his teddy bear," Novia said. "What you knew with Adam is it was a possession. It was not a possession to be put at risk."
Even so, Novia said, his primary concern was that Adam might become a target for abuse by his fellow students, not that he might become a threat.
"Somewhere along in the last four years, there were significant changes that led to what has happened," Novia said. "I could never have foreseen him doing that."
Jim McDade, who lives a few houses from where Nancy Lanza was slain, said his family became acquainted with the two brothers and their mother because their children were about the same ages and rode the school bus together.
"There was certainly no indication of anything unusual that lets you think that a kid's going to do something like that," said McDade, who works in finance in New York. "There was nothing that would indicate anything going on behind the scenes that would lead to this horrible mess."
He recalled Adam Lanza as "a very bright kid."
Olivia DeVivo, a student at the University of Connecticut, was in Adam Lanza's 10th grade English class.
"He was very different and very shy and didn't make an effort to interact with anybody," she said.
DeVivo said Lanza always carried a briefcase and wore his shirts buttoned up to the top button. She said he seemed bright but never really participated in class.
"Now looking back, it's kind of like 'OK, he had all these signs,' but you can't say every shy person would do something like this."
Lanza's family was struggling to make sense of what happened and "trying to find whatever answers we can," his father, Peter Lanza, said in a statement late Saturday that also expressed sympathy for the victims' families.
Associated Press writers Michael Melia and Jim Fitzgerald in Newtown, Conn., Denise Lavoie in Stamford, Conn., and Stephanie Nano in New York contributed to this report.