A former director of security for Newtown Public Schools shed new light Monday night on the gunman, Adam Lanza.
Richard Novia said Lanza had Asperger's syndrome, based on documents and conversations with Lanza's mother, who was killed shortly before the Sandy Hook massacre.
Novia said that as part of his job, which he left in 2008, he would be informed of students who might pose problems to themselves or others.
He also said he received "intake information," which he said "is common for any students troubled or impaired or with disabilities." The idea was to keep track of and help students who may need it.
However, Novia said he never thought Lanza was a threat and certainly never thought he was capable of such violence.
Russ Hanoman, a friend of Lanza's mother, previously told CNN that Lanza had Asperger's and that he was "very withdrawn emotionally."
CNN has not been able to independently confirm whether Lanza was diagnosed with autism or Asperger's, a higher-functioning form of autism. Both are developmental disorders, not mental illnesses.
Many experts say neither Asperger's syndrome nor autism can be blamed for the rampage.
"There is absolutely no evidence or any reliable research that suggests a linkage between autism and planned violence," the Autism Society said in a statement. "To imply or suggest that some linkage exists is wrong and is harmful to more than 1.5 million law-abiding, nonviolent and wonderful individuals who live with autism each day."
Dr. Max Wiznitzer, a pediatric neurologist and autism expert at Rainbow Babies and Children's Hospital in Cleveland, also said the gunman's actions can't be linked to autism spectrum disorders.
"Aggression and violence in the ASD population is reactive, not preplanned and deliberate," he said.
Growing debate over gun laws
What happened in Newtown should never happen again, advocates on both sides of the gun control debate agree. But they're at staunch odds about how to turn words into reality.
The grassroots group Newtown United is sending a delegation to Washington on Tuesday to meet with the Brady Campaign to Prevent Gun Violence as well as families from July's movie theater massacre in Aurora, Colorado.
The new group, which formed out of Newtown on Sunday, aims to create meaningful dialogue -- both locally and beyond -- about what may have led to the tragedy.
Two national polls conducted shortly after the Newtown shootings suggest that more Americans want stricter gun control.A new CBS News poll indicates that 57% of Americans back stricter gun laws, the highest percentage in a decade; 30% think gun laws should be kept as they are.
However, less than half of the respondents in the CBS poll -- 42% -- think stricter gun laws would have helped prevent the massacre at Sandy Hook Elementary.
Sen. Joe Manchin, a conservative Democrat from West Virginia and a "proud gun owner," said he's now committed to "dialogue that would bring a total change" after the massacre in Newtown.