“As long as I knew him, he never really spoke,” said Daniel Frost, who took a computer class with Lanza and remembered his skill with electronics.

Lanza seemed to spend most of his time in his own large space in the basement of the home he shared with his mother — the same basement where she kept a collection of guns, said Russell Ford, a friend of Nancy Lanza who had done chimney and pipe work on the Lanza home.

A week ago, Lanza fatally shot his mother before blasting his way into the school, killing 20 children and six teachers with a military style rifle. As police approached, he used a handgun to commit suicide.

Nancy Lanza was often seen around town and regularly chatted up friends and acquaintances at a local restaurant, but her 20-year-old son was a mysterious figure who was seldom spotted in this community of rolling hills and clapboard colonial homes, according to Ford and other townspeople.

The basement of the Lanza home was fully carpeted and had artwork, including a picture of a horse, on the walls. There was a computer, a flat-screen television, couches and an elaborate set-up for video games. Nancy Lanza kept her guns in what appeared to be a secure case in another part of the basement, Ford said.

“She was from gun culture. Live free or die. That was truly her upbringing,” said Ford, who often met the New Hampshire native and other friends at a regular Tuesday evening gathering at My Place, a local restaurant.

Ford did not know if Lanza brought her son shooting.

Over the past year and a half, Ford said, Nancy Lanza had told him that she planned to move out West and enrol Adam in a “school or a centre.” The plan started unfolding after Adam turned 18.

“He wouldn’t be dwelling with her,” said Ford, who remembered that Adam Lanza never spoke to him or even made eye contact.

“She knew she needed to be near him,” he added. “She was trying to do what was positive for him.”

Ford said Nancy Lanza didn’t elaborate on what type of services she wanted her son to receive. Ford hadn’t seen her in about a month and a half, and said she made fewer appearances at the restaurant in recent months.

Mark Tambascio, owner of My Place, said Nancy Lanza described the same plan to him, saying she might move to Washington state.

Back in high school, Frost recalled, Lanza once made a class presentation about how to change the folders in Microsoft Windows different colours. He did it without saying a word, just demonstrating the steps on a screen.

Someone in the class brought in the video game called “Counter-Strike,” a first-person shooting video game in which players compete against each other as either terrorists or counter-terrorists, Frost said.

Lanza “seemed pretty interested in the game,” Frost recalled, and would play it with other students. He remembers the weapons Lanza chose: an M4 military-style assault rifle and a Glock handgun.

Authorities said Lanza used a military-style assault rifle during the rampage and carried handguns.

A week after the massacre, authorities still have no clear reason why Lanza would lash out at defenceless first-graders and their caretakers. The seemingly random nature of the attack makes it all the more chilling.

State police spokesman Lt. J. Paul Vance said it is too soon to draw any conclusions. A final report on the investigation could be months away.

Lanza destroyed the hard drive of his computer before the attack, and investigators have been unable to retrieve any information from it, according to a person briefed on the case.

And while they haven’t given up, they aren’t confident they will be able to repair it, the person said, speaking on condition of anonymity because he was not authorised to discuss the case publicly.

In Newtown, the community endured another mournful, overcast day filled with multiple funerals and visitations. At the hour of the attack, 9:30 a.m., a bell tolled 26 times on Friday, once for each victim killed at the school.

Governor Dannel P. Malloy gathered with other officials in rain and wind on the steps of the Edmond Town Hall as the bell rang. Officials didn’t make any formal remarks, and similar commemorations took place throughout the country.

Also on Friday, the National Rifle Association spoke out for the first time since the shootings, calling for armed police officers to be stationed at schools to stop the next killer “waiting in the wings.”

Wayne LaPierre, CEO of the nation’s largest gun-rights lobbing group, said at a Washington news conference that “the only thing that stops a bad guy with a gun is a good guy with a gun.”

LaPierre blamed video games, music and videos for exposing children to violence.

At the memorial services, a school psychologist who rushed toward the gunman was remembered as a caring professional, a passionate fan of the Miami Dolphins and a woman who ultimately put the lives of others ahead of her own.

Mary Sherlach’s funeral drew a standing-room-only crowd to St. Stephen Roman Catholic Church in Trumbull.

The church was adorned with a Christmas tree and several wreaths.

“No one has greater love than to give one’s life for his friends,” Rev. Stephen Gleason said. “And she did so in an attempt to save others.”