Every day for the past 22 years, California's background checks have stopped about a dozen felons, mentally ill people and others from buying guns.
When prospective gun buyers stride into California gun stores such as Ron Kennedy's Canyon Sports in Martinez, they must swipe their driver's licenses or state IDs. That sets off a review process that runs their names not only through the same FBI criminal database other states use but also almost 20 other sources, from mental health records to DMV data. It's a check more rigorous than any other state's.
California is also one of only two states -- Rhode Island is the other -- requiring such checks not only for purchases from licensed gun dealers, but also for all purchases at gun shows, or even if you're just buying a gun from a neighbor.
For those reasons, California's universal background check system is being held up by gun control advocates as a model for the rest of the country. Yet in the emotionally charged national debate that has ensued since December's massacre at a Newtown, Conn., elementary school, whether implementing such a system nationwide would prevent similar tragedies and gun crimes remains a bitter point of contention.
Some statistics are clear: Only 1 percent of California's background checks lead to denials, so the system barely reduces the number of guns out there. But the national denial rate is 0.6 percent, so California's checks are obviously much better at preventing people who can't legally own guns from buying them.
"You have to assume that if you stop one person who would otherwise take that gun and kill people, it's been a success," said Rep. Mike Thompson, D-Napa, chairman of the House Democrats' gun violence task force.
But many gun-rights advocates fear universal background checks are nothing more than a prelude to universal registration and perhaps even confiscation.
Wayne LaPierre, executive vice president and CEO of the National Rifle Association, warned during a recent speech in Reno that President Barack Obama "wants to put every private, personal firearms transaction right under the thumb of the federal government."
At a Senate Judiciary Committee on Wednesday, LaPierre sparred with Sen. Dick Durbin, D-Illinois, on the background check issue after LaPierre argued that more checks would simply force law-abiding citizens to pay more fees for the right to own a gun.
Other statistics can be used to support either side of the argument. Consider:
Yet it's hard to draw a direct link between background checks and rates of gun crime or gun deaths. Those rates might also be affected by other California gun laws, including a 10-day waiting period -- most states have none -- meant both to accommodate the expanded background checks and to let any hotheaded buyers cool off before taking possession of a gun. The state also has an assault weapons ban, handgun registration and other gun control measures that other states don't. And some criminologists argue that crime rates have more to do with a state's poverty, joblessness, education or other social factors than its gun control laws.
What does seem clear is that California's background check system functions well -- and could be replicated elsewhere.
Kennedy of Canyon Sports said the state's online system is "relatively flawless" and, in most cases, easy to use.
San Jose Gun Exchange owner Michael Fournier agreed. "I've got no problem with it," he said. "I couldn't sleep at night thinking someone got a gun who shouldn't own one."
Arizona-based gun show promoter Lori McMann said all her California shows have a "transfer dealer" present to handle the transactions, submit information to the state and hold onto the gun during the 10-day waiting period. In other states, she said, her company simply reminds sellers of their obligation to verbally ask buyers whether they're convicted felons or otherwise prohibited from owning a gun.
It might take hiring more federal and state workers to handle the increased workload, McMann said, but imposing a California-like system nationwide "is definitely doable."
But will it help?
"Criminals don't buy guns in gun stores" or at gun shows, Kennedy insisted. "They steal them or have them purchased for them by someone else."
Nor does it seem background checks -- at least, as they are run now in most of the nation -- stop horrific mass shootings.
The Bushmaster semi-automatic rifle that Adam Lanza used to kill 20 kids and seven adults in Newtown was bought legally by his mother at a licensed gun store after she passed a background check.
James Holmes passed background checks with the FBI's National Instant Criminal Background Check System (NICS) to buy the arsenal he carried in August into an Aurora, Colo., movie theater, where he killed 12 and wounded 58. Jared Lee Loughner also passed an NICS check to buy the gun he used to try to assassinate Rep. Gabrielle Giffords, D-Ariz., killing six people and wounding 12.
Both Holmes and Loughner had documented mental problems that were not recorded in the FBI's database, but it's not clear whether they would have been disclosed to California's system.
Some of Obama's recent executive actions and new bills introduced in Congress from both sides of the aisle aim to plug up those holes, pressing states and federal agencies to feed more and better-detailed information into the FBI system.
But the gun lobby opposes any effort to expand that system's use to cover gun shows or private, person-to-person sales -- representing roughly 40 percent of gun sales.
Chuck Michel, spokesman and attorney for the California Rifle and Pistol Association, agreed with LaPierre that "the biggest problem with background check systems is they typically incorporate registration of law-abiding firearm buyer and owners."
It's true that California does, unlike many states, retain information submitted for background checks for handgun purchases. And next year it will start retaining that information from long-gun purchases.
But Thompson said law-abiding people have nothing to worry about and that it all comes down to keeping guns out of the hands of people who shouldn't have them: "If you don't do a check, I don't know how you can do that."
At Thompson's task force hearing last week, David Chipman, a former special agent of the Bureau of Alcohol, Tobacco, Firearms and Explosives, likened the need for universal background checks to the need for heightened air security after Sept. 11.
Said Chipman: "Imagine the frustration of TSA employees if they were told that 60 percent of those getting on a plane would get full security screening and then 40 percent would be allowed to walk right on the plane, and then buildings kept blowing up and we were all like, 'Well, how did that happen?'"