WASHINGTON — The nation’s largest gun lobby, which has stayed mostly quiet since the shootings that killed 26 people at a Connecticut elementary school a week ago, called Friday for Congress to require armed security guards in every school, saying that doing so could prevent acts of mass violence from happening again.

In a defiant and unapologetic speech, Wayne LaPierre, the executive vice president of the National Rifle Association, said Friday that the organization would use its resources to build what he called a “national school shield emergency program.” The NRA’s program will be led by Asa Hutchinson, a former Republican congressman and U.S. attorney from Arkansas.

LaPierre on Friday blamed the Connecticut shooting spree on violent video games and movies, as well as the portrayal of guns and mass shootings in the media and the lack of a comprehensive database of the mentally ill. He also said no-gun zones at schools could invite new attacks by those he described as “monsters and predators.” The only thing stopping a “bad guy with a gun” is “a good guy with a gun,” LaPierre said.

“What if, when Adam Lanza started shooting his way into Sandy Hook Elementary School last Friday, he’d been confronted by qualified, armed security?” LaPierre said. “Will you at least admit it’s possible that 26 little kids, that 26 innocent lives might have been spared that day?”