For one week following the slaughter of 20 schoolchildren and seven adults in Newtown, Conn., the National Rifle Association maintained what could have been considered a respectful if shame-faced silence over the shooting involving weapons including a semiautomatic rifle.

But when Wayne LaPierre, the chief executive of the gun lobby, did break the silence last week, he did everything but acknowledge that a large part of the problem with gun violence is the easy availability of high-powered weapons and high-capacity magazines. The NRA leader refused to concede that any effort to reduce gun casualties in public places, from schools and workplaces to malls, must address the saturation of powerful firearms, such as the Bushmaster AR-15 that enabled Adam Lanza to take so many lives in the space of a few minutes.

“The only thing that stops a bad guy with a gun is a good guy with a gun,” LaPierre said, in calling for legislation to place armed guards in schools. In a nation with more than 250 million firearms in circulation, the NRA essentially argues that arming more people with guns is the only way to pre-empt the kind of rampage that mowed down children in Newtown, moviegoers in Aurora, Colo., and Sikhs in a temple in Oak Creek, Wis.

For the past four years, the NRA has stoked fear about an Obama White House plotting how to take away people’s guns, if not an attempt to repeal the Second Amendment itself. It is disturbing that in the face of a grotesque assault on 6- and 7-year-olds, the gun lobby describes as “phony” and “based on lies” a proposal by Sen. Dianne Feinstein to restore the expired ban on civilian ownership of military-style assault weapons.

LaPierre contends that with a ban on high-capacity weapons, Lanza would have found some other means to kill as many people as he could. Conveniently, he ignored the salient fact that firearms make a murderous spree vastly easier than, say, a knife or baseball bat. According to the FBI Uniform Crime Statistics, 68 percent of murders in 2011 were committed with firearms.

Far from a ban on firearms, which law-abiding Americans possess by the millions, the rational response to events like Newtown and Aurora call for is a reassessment of policies that permit unrestricted access to devastating firepower.