After that, Mr. Lowe hugged Mr. Granados-Diaz for at least 20 seconds, the footage showed.

“Pretty crazy situation,” Mr. Lowe, a former football player for the University of Oregon and former analyst for the Philadelphia Eagles and the San Francisco 49ers, said in a news conference in May, according to KOIN. He added: “In a fraction of a second, I analyzed everything really fast. I saw the look in his face, the look in his eyes. Looked at the gun. Realized it was a real gun and then my instincts just took over. I lunged for the gun.”

Mr. Lowe said students were screaming and running out of classrooms but he made sure the weapon was not aimed at anyone else.

“I think I’ve gone through stuff in my life that prepared me for that moment and I’m lucky and I’m happy that I was in that classroom for those kids and I was able to prevent that tragedy,” he said. “I don’t know if ‘hero’ is the right word but the universe works in mysterious ways and I was meant to be in that classroom.”

Mr. Lowe said during those moments in which he hugged Mr. Granados-Diaz, they had a “real-life” conversation.

“Obviously, he broke down and I just wanted to let him know that I was there for him,” Mr. Lowe said. “I told him I was there to save him — I was there for a reason and that this is a life worth living.”

Mr. Lowe was hailed for his quick assessment of the situation and composure under pressure.

Bruce Alexander, who has worked in law enforcement, government counterterrorism and private security for 30 years, said every second is critical in the type of threat that Mr. Lowe defused.