It comes in black, tan and camouflage. A pink version once was raffled by a gun store to raise money for breast cancer research.
Favored by target shooters in competitions and by hunters who stalk small game and sometimes deer, its customizable features — stocks, grips, sights, barrel lengths — are endlessly discussed by enthusiasts in online forums. It ranks high among the firearms purchased for self-defense.
But the AR-15 style rifle — the most popular rifle in America, according to gun dealers — also was the weapon of choice for Adam Lanza, who police said used one made by Bushmaster on Friday to kill 20 young children and six adults in an elementary school in Newtown, Conn., in a massacre that has horrified the nation.
The increasing appearance of the rifle in rampage killings — police officials say an AR-15 was used by James E. Holmes, who is accused of opening fire and killing 12 people in a movie theater in Colorado in July and by Jacob Roberts, who killed two people and then took his own life in a shopping mall last week near Portland, Ore. — has rekindled the debate about its availability and its appeal to killers bent on mass slaughter.
It also has starkly highlighted the chasm between those who favor tighter regulation for firearms and those who believe that guns like the AR-15 are widely misunderstood and wrongly blamed for the actions of a few individuals.
Gun-control advocates contend that semi-automatic weapons like the AR-15 — the civilian version of the military's M-16 and M-4 — are a logical choice for anyone whose goal is to kill a lot of people in a short time, because of their ability to rapidly fire multiple high-velocity rounds.
“The people we're talking about, once they get into 'I want to kill a lot of people,' it's not a leap for them to see that these guns are made and designed for war,” said Tom Diaz, a senior policy analyst at the Violence Policy Center. “And if you look at the industry advertising, that is a consistent theme.”
AR-15s are not the only weapons used by rampaging shooters. Semi-automatic handguns also are frequently employed. In Newtown, in addition to the Bushmaster M-4 carbine, two handguns were found at the scene, a 10-mm Glock and a 9-mm Sig Sauer, although the rifle is what Lanza used, spraying up to 11 bullets into each victim's body, according to the medical examiner. All three guns belonged to his mother, officials said.
In Colorado, Holmes carried two Glock handguns and a shotgun, officials said, as well as the AR-15. A Glock and a Walther were used by Seung-hui Cho to kill 32 people and injure 17 at Virginia Tech in 2007.
In the wake of the Newtown shooting, Diaz and others have called for a ban on the high-capacity magazines routinely used with such firearms, which feed 20 or 30 rounds at a fast pace.