The father of Adam Lanza said in a magazine interview that he wishes his son was never born, adding that he would have killed him too. Lanza was the gunman who killed himself, his mother and 26 people at the Sandy Hook Elementary School in Newtown, Conn. in December 2012.

Peter Lanza told The New Yorker in his first public comments since that day that he can no longer look at old photos of Lanza. “I’m not dealing with it,” he said. “You can’t mourn for the little boy he once was. You can’t fool yourself.”

He added that his son, who was 20-years-old, would have killed him, too, USA Today notes. “With hindsight, I know Adam would have killed me in a heartbeat, if he'd had the chance. I don't question that for a minute,” Peter Lanza said.

During the interviews with the magazine, which began in September, Peter Lanza admitted the he wished Lanza was never born, reports Reuters.. “That didn't come right away,” he said about that feeling. “That's not a natural thing, when you're thinking about your kid. But, God, there's no question.”

Every night since the day of the shooting, Peter Lanza has had nightmares about his son, imagining the events through the victims’ perspective.

Peter Lanza said he hadn’t seen his son in two years. He said that he has met with a victim’s family member and was amazed that they could forgive him.

“It's gut-wrenching,” he told the New Yorker. “A victim's family member told me that they forgave Adam after we spent three hours talking. I didn't even know how to respond.”