Can troubled youths be spotted before they turn deadly?

(CBS News) NEW YORK - If there's one area of possible agreement in the Senate in the wake of last year's shooting massacre in Newtown, Conn., it's the need for improvements in the treatment of the mentally ill, with a focus on identifying troubled youths before they take a deadly turn.

That Adam Lanza had serious issues before he massacred 26 adults and children was obvious to many, including, apparently, his own mother.

The psychiatrist of accused Aurora movie theater shooter James Holmes was so concerned about his potential for violence, she reported him to campus police.

Yet neither Lanza nor Holmes would have been flagged in a background check. Not Lanza because it was his mother who bought the weapons, and not Holmes because he'd never been institutionalized for mental illness.

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Criminologist James Fox of Northeastern University said mass killers are impossible to spot until after the fact.

"The irony is that these mass killings are the very kind of crimes that are least preventable by the kind of gun legislation we're seeing today," Fox said.

"The odds are that 1 in 4 of us will experience a common mental disorder in our lifetime," said Dr. Gary Belkin, a psychiatrist at New York University. "We can't all be put on a list, so we have to build mental health that is accessible deeply in our communities."

Belkin wants family members, neighbors and teachers empowered to be early warning systems.

"We don't think twice about being trained in first aid," said Belkin. "There is a movement afoot to really put forth a psychological first aid as a skill set that people can have."

Access to treatment is crucial for the mentally ill, psychiatrists say, but so is limiting their access to guns. That would prevent many of the 30,000 suicides and murders committed with firearms every year.