背景审查制度是否有助于减少枪支引起的犯罪？

ROBERT SIEGEL, HOST: From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel.

MELISSA BLOCK, HOST: And I'm Melissa Block.

As President Obama begins his second term, one of his top priorities is gun control. While Americans may be deeply divided on the issue, at least one of the president's proposals seems to have widespread support, his call for background checks on all gun purchases.

NPR's Steve Henn reports on how a universal system would work.

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STEVE HENN, BYLINE: When you walk into Kerley's Hunting and Outfitting in Cupertino, California, you're greeted by a roaring stuffed lion that's leaping at the door. There are rows of rifles along the walls, but the owner isn't quite as fierce as his mascot.

HARRY DWYER III: My name is Harry Dwyer III.

HENN: Dwyer's business is just around the corner from Apple's headquarters, but his shop is much older than Apple.

And how long has Kerley's been here?

III: Since 1969.

HENN: It's an old neighborhood gun shop. To the left of the door is a weathered NRA sign, but there's one thing Dwyer and some gun control advocates might just agree on. He doesn't think convicted criminals or the mentally ill should have easy access to weapons.

III: Certainly, yeah.

HENN: And unlike most states, California has universal background checks for gun buyers.

III: It's been decades that California has had it.

HENN: Here's how it works here. Say I want to sell someone my old shotgun, before we can close the deal, both of us have to go into a federally licensed shop like Kerley's.

III: Both parties are to bring the firearm and all the required documentation to purchase it to a licensed dealer like myself. We run the background check on the buyer and retain the gun for 10 days while that happens.

HENN: California has some of the strictest gun control laws in the country, and gun control advocates argue they've been effective in keeping thousands of guns out of the hands of criminals here. Federal law is supposed to keep guns out of the hands of the dangerously mentally ill, but many say the language in the current law is outdated and confusing at best.

RON HONBERG: People adjudicated as mentally defective is one category. And the second category are people committed to mental institutions. And that's the terminology that's used in that law.

HENN: Ron Honberg is the director of policy and legal affairs at the National Alliance for the Mentally Ill.

HONBERG: Well, the language is horribly stigmatizing. And, in fact, so offensive that it is hard to even discuss the substantive aspects of the law, and it's never been changed.

HENN: Honberg also says it's not particularly helpful to officials who have to decide who should and shouldn't be allowed to buy a gun.

HONBERG: It's very unhelpful. And the reason its unhelpful is because no one really understands what it means.

HENN: In 2007, the shooter at Virginia Tech passed two separate background checks without a problem, even though two years earlier he had been found to be a danger to himself and others. Confusion over the language in the law meant his name was never added to the federal database. After those shootings, Congress took steps to encourage states to beef up reporting.

But Philip Cook who studies gun violence at Duke says...

PHILIP COOK: Mental health records are woefully incomplete. There are something like 30 states that do not submit records.

HENN: Even now, six years after Virginia Tech. Criminal reporting is better but it's still not perfect. And Cook says even when all these records are accurate and up to date, the current system doesn't do a very good job predicting and preventing future gun crime. He recently completed a study of alleged murderers in the in Chicago.

COOK: What we found was that only 40 percent of them had a felony conviction in the preceding 10 years.

HENN: Most of these people could legally buy guns. Cook argues if background checks are going to be effective, they'll have to become more robust. He believes background checks should examine juvenile records, any violent crimes, even histories of alcohol abuse.

Steve Henn, NPR News.