See the complete list of victims' names released by Connecticut police
The parents of Adam Lanza were concerned about his well being. A mediator who worked with the parents says Lanza had been diagnosed with Asperger's syndrome.
Lanza had lived with his mother in Newtown. His parents divorced in 2009, but those close to the family said there was no indication of bitterness or anger between the couple. But the very same guns Nancy Lanza kept for target shooting and for safety were the ones her son used to murder her.
Nancy Lanza was his first victim. Then he went on a shooting massacre that left 20 children and six adults dead at Sandy Hook Elementary.
See photos from the Sandy Hook school shooting in Connecticut
Friends say Nancy Lanza taught her son how to use the weapons. She took him to the shooting range. They said her interest in guns was just a safe hobby.
"I've seen a lot of things in the media about her being this survivalist wacko and that was not her at all," said Russ Hanoman, a friend of the slain woman. "She told me repeatedly how obsessed Adam was about holding the gun the correct way, so it would be safe if the gun was up. Safety was paramount always."
A young Adam Lanza was so opposed to killing he would not even eat any meat. He was a vegan, says one family friend.
Newly obtained divorce records indicate Nancy Lanza was well provided for. Her alimony this year was scheduled to be $289,000. She was given final authority to make decisions on how her son would be raised. For a while, she taught him at home according to an in-law.
"She eventually would up homeschooling him because she battled with the district," said the woman's sister-in-law, Marsha Lanza. "In what capacity, I'm not 100 percent certain if it was behavior or learning disabilities. He was a very bright boy. He was smart."
Ryan Kraft of Hermosa Beach used to be Adam Lanza's neighbor and babysat him more than a decade ago. He described the boy as an introverted, painfully shy kid who seemed to be in his own world.
"I also remember that his mom, Nancy, had always instructed me to keep an eye on him at all times, never turn my back," Kraft said. "But looking back, I guess there was something else going on."
Officials say there was no connection between Adam Lanza and Sandy Hook Elementary School, where investigators continued their work Monday. The motive behind Friday's shooting remains a mystery.