NEWTON, Conn. -- In the aftermath of one of the worst school massacres in U.S history, authorities are trying to piece together a profile of Adam Lanza and what drove the 20-year-old to shoot his mother Friday morning, then shoot his way into Sandy Hook Elementary School and kill 26 students and faculty before committing suicide.
As many in this bucolic town of 27,000 were grieving and grappling for answers and much of the nation mourned, authorities were still searching for a motive. Law enforcement officials say Lanza suffered from a personality order. Family friends say he had Asperger's Syndrome.
Some media reports say Lanza had a confrontation with someone at the school days ahead of the shooting spree, but authorities said Saturday they had no information regarding an incident and had found no suicide notes or manifesto.
Family and friends say Lanza was many things -- intelligent, nerdy, goth, remote, thin. He did not appear to have a job and had no criminal record.
One of Lanza's middle school classmates at Newtown Middle School, who requested anonymity, described him as smart, but odd, more animated and less social than other students.
Lanza, whose mother, Nancy Lanza, was found dead at her home Friday, attended Newtown High School, and news clippings from recent years show him an honor roll student. Joshua Milas, a classmate who was in the technology club with Lanza, said that he was generally a happy person, but that he hadn't seen him in a few years.
"We would hang out, and he was a good kid. He was smart," said Milas, who graduated in 2009. "He was probably one of the smartest kids I know. He was probably a genius."
The tech club held parties at members' homes, hooking up their computers to play games. Gloria Milas, Joshua's mother, hosted one of the parties. She recalled a 2008 school meeting organized by Nancy Lanza to try to save the job of the club's adviser. At the meeting, Milas said, Adam Lanza's brother Ryan said a few words in support of the adviser, who he said had taken his brother under his wing.
"My brother has always been a nerd," Ryan Lanza said then, according to Milas. "He still wears a pocket protector."
Ryan Lanza, who lives in Hoboken, N.J., was questioned by authorities Friday. He said he had last seen Adam in 2010.
Catherine Urso, who attended a vigil Friday evening in Newtown, Conn., said her college-age son knew the killer and remembered him for his alternative style.
"He just said he was very thin, very remote and was one of the goths," referring to a style of dress noted for a heavily black wardrobe.
Authorities say Adam Lanza shot his mother at their home before driving her car to Sandy Hook Elementary School and - armed with at least two handguns - carried out the massacre, officials said.
A third weapon, a .223-caliber rifle, was found in the car, and more guns were recovered during the investigation.
Nancy and husband Peter Lanza filed for divorce in 2008. They were divorced in 2009 after 28 years of marriage due to "irreconcilable differences,'' according to court records. Peter Lanza is a vice president of taxes for GE Energy Financial Services. Adam was 17 at the time of the divorce.
Lanza's aunt Marsha Lanza, of Crystal Lake, Ill., said her nephew was raised by kind, nurturing parents who would not have hesitated to seek mental help for him if he needed it.
If her son had needed counseling, "Nancy wasn't one to deny reality," she said.
Lanza said she was close with Nancy Lanza and had sent her a Facebook message Friday morning asking how she was doing. Nancy Lanza never responded.
Nancy Lanza's mother was too distraught to speak when reached by phone at her home in Brooksville, Fla.
"I just don't know, and I can't make a comment right now," Dorothy Hanson, 78, said.