Profiler: Conn. shooter's warning signs likely ignored

(CBS News) Police have yet to reveal what might have driven gunman Adam Lanza to kill 27 people, including 20 children, and then himself. But are there any clues?

Mary Ellen O'Toole is a former senior profiler for the FBI and author of "Dangerous Instincts: How Gut Feelings Betray Us." She spoke to the "CBS This Morning: Saturday" co-hosts about the tragedy at Sandy Hook Elementary School, and how and why someone would take the lives of so many children.

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O'Toole said that, based on what is known right now, there does appear to be some relationship that Lanza had with the school, which possibly came from his mother.

"Going in and killing what's important to the mother could have been one of the primary motives behind targeting those specific children," she said. "From the perspective of the shooter, they make perfect victims, perfect targets. It's a horrible thing to say, but behaviorally, that's probably the element for him."

As the investigation continues, O'Toole also expects certain warning behaviors will be revealed -- behaviors that were ignored, rationalized or explained away by those around Lanza.

So, could this have been prevented?

"When we talk about warning signs... to the schools, what we tell them is, 'Look, don't vet these warning signs yourself,'" she said. "Call law enforcement. Let them vet them, investigate them. Because you may have just one piece of the puzzle."

For the full interview with profiler Mary Ellen O'Toole, click on the video player above.