Nancy Lanza, the mother of the Sandy Hook shooter, was in the process of having her son committed to a psychiatric facility when he went on the mass shooting spree, a lifelong family acquaintance told Fox News.
A senior law enforcement official also confirmed that 20-year-old Lanza's anger over his mother's plan is being investigated as a possible motive for the Newtown shooting.
"From what I've been told, Adam was aware of her petitioning the court for conservatorship and (her) plans to have him committed," said Joshua Flashman, 25, who grew up not far from where the shooting took place. "Adam was apparently very upset about this. He thought she just wanted to send him away. From what I understand, he was really, really angry. I think this could have been it, what set him off."
It's unclear whether Adam's mother, Nancy Lanza, was really filing the paperwork, because court officials say that such records are sealed. But she would have gone through a longer process to get legal rights to commit an adult to a hospital or psych ward against his will.
UPDATE: The New York Daily News reports that an unidentified friend claims Adam was withdrawing from his mother -- and the world -- in the days leading up to the killings. The person, who claims to be close to Nancy Lanza, said that the mother took Adam to a psychiatrist, but wasn't planning on committing him to a facility. Neither report has been confirmed by named police sources.
Nancy Lanza reportedly volunteered with kindergartners at the school for several years. Flashman said that Adam "believed she cared more for the children than she did for him." On the day of the massacre, Nancy was Adam's first victim. Flashman told Fox News that Nancy was also good friends with the school's principal and psychologist, both of whom were killed during the incident.
Lanza had also reportedly cut off communication with his father, Peter, in 2010.
RELATED ON HUFFPOST:
Don’t miss out — be the first to know all the latest and breaking news. Learn more