(CNN) -- He's being hailed as a hero, a teacher who stared down the barrel of a shooter's gun.
And were it not for his bravery, authorities say, the horror that unfolded at Berrendo Middle School in Roswell, New Mexico, could have been worse. Much worse.
John Masterson, a social studies teacher, is credited with talking a 12-year-old suspect into putting down his shotgun during a shooting at the school Tuesday.
Masterson has taught at the school for a decade, and also coaches track and soccer, according to the Albuquerque Journal.
When contacted by the newspaper, he said police told him not to discuss details of the shooting.
"It was a harrowing experience," he told the paper. "All I can say was the staff there did a great job."
New Mexico Gov. Susana Martinez was more forthcoming.
Masterson, she said, walked up to the shooter and convinced him to put the gun down.
"Mr. Masterson ... was a hero ...who stood there and allowed a gun to be pointed right at him," the governor said at a vigil Tuesday evening, "and to talk down that young boy to drop the gun so that there would be no more young kids hurt."
Police don't yet know why the suspect, a 7th grader, walked into the crowded gym at the beginning of the school day and opened fire.
Kendal Sanders, 13, and an 11-year-old boy were injured in the shooting, the latter critically. His name has not been released.
"Then he shot up in the sky, then dropped the gun, and then some teacher grabbed the kid that had the gun," eighth-grader Odiee Carranza told the paper.
"(He) walked right up to him and asked him to put down the firearm," the governor said about Masterson.
But he wasn't the only teacher who put the schoolchildren's safety ahead of his.
Another school staff member suffered "very minor injuries" in the shooting and declined medical treatment so he could continue to care for the pupils in the gym, the governor said.
"It's one thing for a armed state police officer to enter a school and do his or her job," said State Police Chief Pete Kassetas. "It's another thing for a teacher, staff member to intervene in a situation like this."