Adam Lanza who killed 27 children and adults in Connecticut has been described by former classmates as troubled, withdrawn, and completely isolated.
In light of the shooting, the issue of access to mental health care has gotten a lot of attention.
Advocates say school districts are tasked with providing diagnosis and care, but often lack the resources to do the job.
Federal law requires school districts to identify and help children with special needs -- and that includes behavioral and mental-health needs. For many kids, school is the only place where they get mental-health services, says Amy Smith, president of the National Association of School Psychologists.
"Statistically, about 70 to 80 percent of children who need mental-health services receive those services in schools, because they don't have access to them in other ways," she says.
Often, though, the resources to do this daunting job are lacking, Smith said. School psychologists and guidance counselors are often the first to be cut during tough budget years.
A heavy burden on financially strapped schools
That places a huge burden on schools, says Josh Kershenbaum, a special education lawyer in Conshohocken.
"We have placed them in the position of being responsible for identifying and evaluating and properly educating all children," he explained. "So long as we're going to continue doing that, we need to make sure that the funding, training and resources are available to all school districts because we're going to pay for it one way or another."
Kids who don't receive appropriate services don't go on to become mass murderers, but they often end up troubled and unsuccessful in life, he said. And, Kershenbaum said, it's time for school districts to review their responsibilities when it comes to serving children with mental-health needs.
"Do they have the procedures and resources in place?" he said. "Do they have training on the level of the guidance counselors and the school psychologists and the teachers to identify the signs that a child might be in crisis?"
He says he hopes the tragedy will inspire a national conversation on the huge responsibility lawmakers have given schools, and what will allow them to succeed in getting kids the help they need.