Urging Congress to expand background checks for gun buyers, President Obama claims the current system has "kept more than 2 million dangerous people from getting their hands on a gun" during the last two decades. If you understand why that claim is misleading, you will understand why background checks are not an effective way to stop criminals from obtaining weapons.
It's true that more than 2 million gun sales have been blocked since 1994 as a result of the background checks mandated by the Brady Act. But judging from the way law enforcement officials treat them, these people typically are not "dangerous."
Anyone who buys a firearm from a federally licensed dealer has to fill out a form attesting that the transaction is permitted by federal law, which bars gun ownership by felons, fugitives, illegal drug users, illegal immigrants, and people who have been involuntarily committed to mental hospitals, among other prohibited categories. Although lying on this form is a felony punishable by up to five years in prison, sales blocked by the National Instant Criminal Background Check System (NICS) rarely result in a federal investigation, let alone prosecution.
According to a 2004 report by the Justice Department's inspector general, the most common reason the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) chooses not to pursue these cases is that the buyer does not seem to pose a threat. "The special agents we spoke with generally commented that they do not consider the vast majority of NICS referral subjects a danger to the public," the report said, "because the prohibiting factors are often minor or based on incidents that occurred many years in the past."
The ATF's handling of NICS referrals reflects two facts commonly ignored by background-check enthusiasts. First, the criteria for stripping people of their Second Amendment rights are absurdly (and unfairly) broad, sweeping pot growers, hubcap thieves, and guys who got into a bar fight 20 years ago together with violent predators. Second, criminals generally do not buy their weapons in gun stores.
Even in surveys conducted before the Brady Act, only a fifth of state prisoners who had used guns to commit crimes said they bought them from licensed dealers. In a 2004 survey, the share was just one-tenth.
Furthermore, a criminal turned away by a licensed dealer can always steal a gun, buy one from someone who does not run background checks, or ask someone with a clean record to buy one for him. Obama is therefore doubly wrong to equate blocking sales through NICS with preventing "dangerous people" from "getting their hands on a gun."
Given these realities, it is not surprising that a 2000 study by criminologists Philip J. Cook and Jens Ludwig found no evidence that the Brady Act had an impact on homicide rates. But according to supporters of expanded background checks, the problem is that the Brady Act did not go far enough.
One difficulty with that argument: As Cook and Ludwig note, most people who use guns to commit crimes—including almost all mass shooters—could have passed a background check. But what about the rest? Would they be thwarted by a broader screening requirement?
Probably not. Forcing private sellers at gun shows to arrange background checks with the help of licensed dealers is relatively straightforward. But in that 2004 inmate survey, less than 2 percent of respondents said they had bought weapons at gun shows or flea markets.
Three sources accounted for almost nine out of 10 crime guns: "friends or family" (40 percent), "the street" (38 percent), and theft (10 percent). It is hard to see how any notional background check requirement, even one applying to all private transfers, can reasonably be expected to have a significant impact on these sources. As usual with gun control, the attempt to enforce such a requirement would impose costs and uncertain legal risks on law-abiding gun owners while leaving criminals free to go about their business.