He never did.
A new investigation, co-reported by the Hartford Courant and PBS Frontline, plunges into the minutiae of one of America's most mysterious families -- mysterious perhaps solely because of the massacre Adam Lanza, 20, perpetrated in Newtown, Conn., which left 26 dead at the school, plus himself.
Before the attack, he had shot his mother four times at their home, where police said they found thousands of dollars worth of violent video games -- as well as news articles about Norwegian mass murderer Anders Breivik, the Courant reported after publishing its investigation.
Yet the games and the articles amount to the only publicly known traces of evidence that point to speculative motives for Adam Lanza, who was diagnosed with Asperger's syndrome and sensory integration disorder.
A final police report on the killings has yet to be published, and Connecticut police called the Breivik connection mere speculation. Video games are a multibillion-dollar-a-year industry, and some criminologists say mass killings are no more frequent since the games' popularization. Some studies have shown a mild increase in aggression after playing violent video games, but mass shootings have been too rare to provide any kind of scientifically sound findings.
The Courant's 6,000-word portrait of the family focuses less on what happened at the school and instead tills through the decades that preceded the slaughter. Adam Lanza was extraordinarily shy and repulsed by human contact, and Nancy Lanza shuffled him through various schools and educational programs, to varying success.
In recent years, after a separation from Adam's father, Nancy Lanza had taken to increased travel and often stayed at nice hotels, away from her son often for days at a time. Few people entered their home in Newtown.
For Adam's part, the Courant reported, he had taken up studying Chinese and learning to play musical instruments, at one point working part-time at a computer-repair shop in Newtown.
The family had long been familiar with guns as a hobby, a point that became contentious shortly after the massacre.
"She's been described as some kind of survivalist, or a prepper who was preparing for the government and economy crumbling, which was simply not the case," John Bergquist, a friend of Nancy Lanza's, told the Courant.
Nancy Lanza had told friends she was thinking about moving out of the Northeast with Adam to enroll him in a university but never got around to making the move.
Adam Lanza's massacre left behind a father, Peter Lanza, and a brother, Ryan Lanza, who was wrongfully implicated for the attack in initial reports.