NEWTOWN, Connecticut -- Nancy Lanza was raising a quiet, socially awkward young man, the kind of teenager who, a former classmate recalled, would just go stand in the corner.
Lanza herself seemed nothing like her boy. She was affable and outgoing, and easily made friends.
Sure, she liked guns, say people who knew her. But she was responsible with them. She knew how to handle the weapons she collected.
How Adam Lanza allegedly got hold of at least a few of them to commit a massacre in an elementary school is still unclear.
Authorities believe he shot his mother as she slept in her bed. Then, authorities say, Adam Lanza went to Sandy Hook Elementary -- where he'd once attended -- and mowed down 20 children and six adults.
Then, authorities say, he killed himself.
On Monday, just a few days after that horror, a former classmate of Adam Lanza told CNN that he bumped into Nancy Lanza awhile ago.
Alan Diaz, 20, asked her how her son was doing.
To Diaz, it seemed that Adam Lanza just disappeared from high school after his sophomore year, but it turns out Lanza, then 16, was taking classes at Western Connecticut State University, a school spokesman said.
It was hard to forget a kid like Adam Lanza.
"I would call him a genius," Diaz said.
Lanza got a 3.26 GPA at WCSU, including an A in a computer class, the school spokesman told CNN, but Lanza took his last class in 2009 and didn't come back.
When Diaz and Lanza were classmates, Diaz went out of his way to include Adam Lanza when few others would, he said.
It worked, for a little while.
Lanza opened up, sometimes telling jokes to the other students. There he'd be, in the same plaid green button-up shirt and his khakis -- the weird kid, telling jokes.
So those few years later, seeing Adam Lanza's mother, Diaz just had to ask. How are things going with Adam?
"When I talked to Nancy that time, about how he was doing, she said he's been going to the (gun) range a lot recently," Diaz told CNN. "That he'd taken that up as a hobby."
Guns and Gardening
Nancy Lanza was a personable neighbor, acquaintances said. Sandy Hook is an affluent area about 60 miles from New York City.
The homes are huge and so are the yards.
It's the kind of neighborhood where Christmas cookies are exchanged and people get together at each others' houses.
When Connecticut winters bring blankets of snow, the kids ride sleds on a big hill in the neighborhood.
Nancy Lanza and her two boys -- Ryan and Adam -- and her husband, Peter, moved there around 1998.
The couple divorced in 2009. Peter Lanza is listed on LinkedIn, as a tax director and vice president of taxes for GE Energy Financial Services in the New York City area. According to divorce documents, he agreed to pay his wife, on average, $250,000 a year in alimony. He also agreed to buy his son Adam a car, though his wife would have to pay for the vehicle's upkeep and insurance.
Adam Lanza's primary residence was with his mother, the documents show. They lived in the Newtown home that Peter Lanza ceded to Nancy.
The father was also responsible for paying for Adam's college, as well as for Ryan Lanza's schooling.
Peter Lanza and his other son, Ryan, were both questioned after Friday's rampage.
A 'normal' family and target shooting
"It was just a nice, normal family," neighbor Rhonda Cullen said Saturday, recalling how she and other women on the street would often go to each others' houses to play cards.
Nancy Lanza preferred to garden.
"We used to joke with her that she'd do all this landscaping that no one could see because it all was in the back (of the house)," Cullen said.
Nancy Lanza was also into collecting guns, say those who knew her.
Dan Holmes, who owns a local landscaping business, said she showed off a rifle she recently purchased.
"She told me she'd go target shooting with her boys pretty often," Holmes said.
Nancy Lanza kept a lot of weapons, from assault rifles to handguns, at her home.
The weapons were for self-defense, said Marsha Lanza, Peter Lanza's sister.
Yet, Marsha Lanza said her former sister-in-law "never felt threatened." If she did, Marsha Lanza said, Nancy would have spoken up about it.
Nancy was self-reliant, a trait that she possibly picked up while growing up on a farm in New Hampshire, Marsha Lanza said.
At some point, she worked in finance in Boston and Connecticut, a friend said.
She was not a teacher, as some media had previously reported, the friend added.
Despite whatever problems Nancy Lanza might have been facing behind closed doors, on the outside she kept a cheerful face. Several people who knew Nancy Lanza said she was incredibly social and warm.
Several nights a week, she got take-out from My Place bar in Newtown.
CNN sat down with owners Louise Tambascio, Mark Tambascio and John Tambascio.
Louise recalled Nancy starting a conversation with her, and how they become fast friends.
"She's funny. We took to her," said