(AP Photo/NBC News, File) (AP Photo/NBC News, File)

“With hindsight, I know Adam would have killed me in a heartbeat, if he’d had the chance,” Peter Lanza said in a series of interviews for the March 17 issue of the New Yorker magazine.

The piece, “The Reckoning: The Father of the Sandy Hook Killer Searches for Answers” by Andrew Solomon, is a powerful narrative of the family’s troubles.

It’s the first time Peter Lanza has spoken publicly about his son.

“It was crystal clear something was wrong,” the article quotes the father as saying.  “The social awkwardness, the uncomfortable anxiety, unable to sleep, stress, unable to concentrate, having a hard time learning, the awkward walk, reduced eye contact. You could see the changes occurring.”

Adam Lanza shot his mother, himself, and twenty-six people at Sandy Hook Elementary School in Newtown, Connecticut, in December 2012.

But Lanza says he and his wife, and even mental health professionals, didn’t recognize the violent tendencies in his son. Lanza said his son’s Asperger’s was not to blame and suspects the condition “veiled a contaminant.”

“I want people to be afraid of the fact that this could happen to them,” he said.

“Peter declared that he wished Adam had never been born,” Andrew Solomon writes. “That didn’t come right away,” Lanza said.”That’s not a natural thing, when you’re thinking about your kid. But, God, there’s no question.”