3-D打印塑料枪带来安全隐患

STEVE INSKEEP, HOST: We're also following stories closer to home like this one. Technology helps police to solve crimes every day, but some innovations can also present new public safety concerns, like guns built using 3D printers. Agents at the Bureau of Alcohol, Tobacco and Firearms have spent months testing plastic weapons, and in findings released on Tuesday they say guns are both lethal and hard to detect when made with these printers. NPR's Carrie Johnson reports.

CARRIE JOHNSON, BYLINE: It can take a top of the line 3D printer just 18 hours to build parts for a plastic gun, a gun made out of strong and flexible material with bullets that can penetrate a person's vital organs. Richard Marianos is assistant director at the Bureau of Alcohol, Tobacco and Firearms, or ATF.

RICHARD MARIANOS: When these 3-D firearms are manufactured, some of the weapons can defeat normal detection such as metal detectors, wands, and it could present a problem to public safety in a venue such as an airport, an arena, a courthouse.

JOHNSON: Federal agents say they aren't too worried about a gang member or ordinary felon getting his hands on a plastic gun. But for a certain type of criminal, taking the time to buy or lease a 3-D printer could be worth the trouble. In Texas, a company called Defense Distributed has put instructions online for making a handgun almost entirely out of plastic.

Company founder Cody Wilson didn't respond to interview requests, but he cooperated with a recent documentary made by the online magazine and video channel Motherboard.

CODY WILSON: If we make a Second Amendment argument, it's all the way, it's to the limit, but I don't like to make it about the Second Amendment or gun control at all. It's more radical for us. Like there are people from all over the world downloading our files and we say good. You know, we say you should have access to this.

JOHNSON: There's nothing illegal about building your own gun at home, and some plastic weapons have been available since the 1970s, but they have always used metal in parts like the trigger and hammer. The difference now is that the technology is so good and so cheap that plastic guns are beginning to present more of a danger to the public and less of a risk to the person firing the makeshift weapon. Again, the ATF's Richard Marianos.

MARIANOS: Some of the polymers at the low-grade level actually could blow up in the hands of an individual if they tried to use one for any type of purpose. Some of the harder polymers or the more aggressive compounds were able to fire multiple rounds that create an additional danger to the American public.

JOHNSON: There's something else. A 1988 law that requires guns to be composed of at least some metal to help people in schools and airports detect them is set to expire early next month. Meaning the four ounces or so of metal in Cody Wilson's Liberator handgun that makes the gun comply with current law will not be necessary if Congress fails to act by December 10. New York Democratic Rep. Steve Israel, for one, is worried.

REPRESENTATIVE STEVE ISRAEL: I always say the genie's out of the bottle, why do we need a new law? Well, I'll tell you why we need a new law. If it's easy to make plastic guns, we want to make it harder for them to get past metal detectors and onto our planes.

JOHNSON: Israel says the law has been reauthorized twice, including back in 2003, during the George W. Bush administration. But the odds this polarized Congress will act before the deadline early next month are slim. The ATF says it's working with airport security, the Secret Service and other law enforcement partners to do more training about how to detect plastic guns and stay on top of this new technology. Carrie Johnson, NPR News, Washington.

INSKEEP: Carrie Johnson is NPR's justice correspondent and one of the team of correspondents you hear on MORNING EDITION from NPR News.