The Limits of Gun Control in the Wake of the Sandy Hook Massacre

Outrage does not make ill-conceived policies smarter or more effective.

"These tragedies must end," says President Obama, referring to Adam Lanza's horrifying assault on Sandy Hook Elementary School in Newtown, Connecticut, last Friday. Although it is hard to disagree with that sentiment, the measures Obama favors cannot reasonably be expected to prevent such thankfully rare but nevertheless appalling outbursts of senseless violence. 

After the massacre, Press Secretary Jay Carney reiterated Obama's support for reinstating the federal "assault weapon" ban that expired in 2004, and Sen. Dianne Feinstein (D-Calif.) promised to introduce a bill aimed at doing so next month. But we know for sure that an "assault weapon" ban would not have stopped Lanza or made his attack less deadly, because it didn't. 

The rifle that Lanza used, a .223-caliber Bushmaster M4 carbine, is legal under Connecticut's "assault weapon" ban, and the federal law used the same criteria. Except for specifically listed models, both laws cover semiautomatic rifles with detachable magazines that have at least two of these five features: 1) a folding or telescoping stock, 2) a pistol grip, 3) a bayonet mount, 4) a grenade launcher, and 5) a flash suppressor or threaded barrel. 

The fact that such features have little or no functional significance in the context of violent crime reveals the folly of trying to distinguish between "good" and "bad" guns. Any gun that can be used for self-defense or other legitimate purposes also can be used to murder people. 

Guns like Lanza's, modeled after the Colt AR-15, are among the most popular rifles in America, with an estimated 3.5 million sold since 1986. Only a tiny fraction of them are ever used in crimes. 

Prior to the federal "assault weapon" ban, firearms covered by the law were used in something like 2 percent of gun crimes, and these were mostly pistols, according to a 2004 study sponsored by the National Institute of Justice (NIJ). FBI numbers indicate that rifles of any kind (not just "assault weapons") are used in less than 3 percent of murders. Even killers with multiple victims are much more likely to use ordinary handguns than "assault weapons." 

I use those scare quotes because the very term assault weapon was invented by the anti-gun lobby as a way of blurring the distinction between semiautomatic firearms, which fire once per trigger pull, and machine guns such as the selective-fire assault rifles carried by soldiers. The president himself either does not understand the difference or deliberately obscures it, calling upon Congress to ban "AK-47s" and "automatic weapons."   

Given the fraudulent rationale for the "assault weapon" ban, it's not surprising that the NIJ study found little evidence the law had reduced gun violence. "Should it be renewed," University of Pennsylvania criminologist Christopher Koper and his co-authors concluded, "the ban's effects  on gun violence are likely to be small at best and perhaps too small for reliable measurement." 

That was so even when taking into account another aspect of the law that Obama wants to restore: its ban on magazines that hold more than 10 rounds. While it is debatable whether the few seconds it takes to switch magazines or guns makes an important difference in attacks on moviegoers in a darkened theater or on first-graders in an elementary school, Lanza did use 30-round magazines, and this restriction at least looks like a relevant response to mass shootings. 

So many large-capacity magazines are already in circulation, however, that it's hard to see how reinstating this ban would stop a determined killer from obtaining them. Even when the ban was in force, Koper found, there was "an immense stock" of about 30 million such magazines, and the number surely has risen since then. 

Likewise, with around 300 million guns in circulation, there is not much that new laws can do to prevent a man bent on slaughtering innocents from obtaining one. The understandable grief and anger provoked by the Sandy Hook massacre does not change that unavoidable reality.