BOSTON -- People are bypassing background checks to build their own powerful military assault-style rifles -- and it's all legal.
A man used a so-called "ghost gun" in a deadly mass shooting in California in November.
That man, who killed his wife and four others, was prohibited from owning a gun based on prior arrest, but he simply ordered the parts on the internet, and built one himself. No questions asked.
Boston 25 News found out just how easy that is to do.
These so-called “ghost guns” look like an assault rifle you'd buy in a gun store, and fire like one too.
But here's the difference: there's no serial number, no identification needed, no background checks and it can be built at home.
"What these companies are doing is trying to exploit a kind of technical loophole in federal law," said Adam Skaggs with the Giffords Law Center to Reduce Gun Violence.
Boston 25 News found many online businesses that sell all the parts for an unfinished rifle. Of the three we called, two said they would ship to Massachusetts.
Our sister station in Atlanta ordered a kit for $500. It arrived by U.S. mail, neatly packed and ready to assemble. Instructions called for hollowing out the trigger pocket, that holds the key parts of the gun, including the firing mechanism.
Using an ordinary hand drill and a $60 router purchased at a hardware store, the gun was ready for range in less than two days.
"We seize hundreds of these and the number's been going up every year," Graham Barlowe with the Alcohol, Tobacco, Firearms and Explosives Bureau said.
Police said a rising number of criminals are making "ghost guns," selling them and using them in violent attacks across the country.
"We have found 'ghost guns' or firearms made from unfinished receivers used in some horrific crimes," Barlowe said.
Authorities say Kevin Neal used an AR-15 he built himself in the California shooting rampage that left five people dead.
Though his criminal history forbid him from owning a gun, he ordered the assault rifle kit online, no background checks, no questions asked.
"We see this trend becoming more popular and we do see an increase in the number of people selling these," Barlowe said.
It's illegal to sell homemade guns, but making them is completely within the law.
Former Congresswoman Gabby Giffords was gravely wounded in a mass shooting that killed six people in 2011. Since then, she has started the Giffords Law Center to Reduce Gun Violence, which is represented by Adam Skaggs.
Skaggs said "ghost guns" represent a menacing loophole in the law.
"These sites make it as easy as clicking a mouse for these dangerous people to get a hold of assault weapons," Skaggs said.
The Giffords organization has sent letters to web-hosting companies of six sites that sell "ghost guns" asking them to disable the sites.
Some gun rights activists say, they don't think "ghost guns" represent a loophole in the law.
“The thing of it is, any criminal who wants a gun is going to get a gun. He's going to steal it. He's going to buy it off the streets," Jerry Henry with Georgia Carry.org said.
Henry said he believes the vast majority of people who purchase them are hobbyists who enjoy building their own firearms.
Newton resident and founder of Stop Handgun Violence John Rosenthal disagrees, blaming a lack of federal oversight for the "ghost gun" loophole.
Rosenthal calls Massachusetts a model state, with some of the strictest gun laws in the country, and says the lack of serial numbers is a huge issue.
“It's incredible that Congress thinks its OK for these 'ghost gun' manufacturers to make a product specifically designed so it can’t be traced without a serial number and to evade state laws,” Rosenthal said.
Under federal law, no serial numbers are needed on firearms that are built for personal use, but under Massachusetts law, all large capacity guns, even homemade ones, must be registered with a serial number.
Failing to do so, is a criminal offense
In California, where the deadly shooting happened in November, buyers of unfinished guns will soon be required to apply for a serial number for the weapon as well.
Cox Media Group