He then turned to two large flat-screen monitors and played scenes from a crude 2002 Flash game, "Kindergarten Killer," which isn't something most Internet users would ever come across, but is easy to find once you know the name. It involves playing the role of a school janitor and shooting young children who themselves have guns.
"You begin your killing spree, first killing the kindergarten teacher. But then for some unknown reason the kids pull out their own guns!" reads the game's instructions as the player enters level one. "They're outnumbering you, so kill them off and get you of the halls quick! However, you still want to keep your plans of killing the head of the kindergarten, so get to the tower block where his office is. But be careful, those pesky kids are everywhere."
"It's been online for 10 years. How come my research department could find it and all of yours either couldn't or didn't want anyone to know you had found it?" he said, addressing the reporters in the room, from whom he refused to take questions.
LaPierre also criticized violent movies and music videos.
"And then [the media] have the nerve to call it 'entertainment.' But is that what it really is? Isn't fantasizing about killing people as a way to get your kicks really the filthiest form of pornography?" he said.
LaPierre's comments sought to push blame for mass shootings from guns alone to other aspects of American life, although the same games, TV shows and music videos available here are available in other countries that rarely suffer from gun violence. The difference in those countries is that it's difficult or impossible for the general public to get hold of firearms.
The "Kindergartner Killer" game, shocking as its premise is, appears to be a game of minor popularity, simply programmed, that few have probably heard about.
The much more famous titles, like those mentioned by LaPierre, are likely to get more attention.
One of the most popular franchises, Activision's "Call of Duty," outsells most Hollywood movies. The most recent installment of the game, which typically puts the player as a soldier fighting other soldiers, racked up sales of $1 billion in its first 16 days on the market.
LaPierre's statement was framed around a call for more guns at schools to protect children from gunmen. That brought quick criticism from several groups, including the U.S. Conference of Mayors.
"NRA officials today blamed everyone but themselves for the conditions that permitted the monstrous attack on the children and teachers in Sandy Hook Elementary School. They said that gun laws don't work and that pursuing legislation is a waste of time. They proposed instead the equivalent of an arms race," the group said in a statement.