Amid rise in "ghost guns" in Colorado, ATF makes historic rule changes on gun sales

"Ghost guns" — or guns that are pieced together at home, lacking a serial number — are becoming increasingly common in Colorado and the U.S. Last year, nearly 20,000 ghost guns were confiscated in criminal investigations around the country, according to the Bureau of Alcohol, Tobacco, Firearms and Explosives. 

Nearly all ghost guns recovered at crime scenes — more than 99% — can't be traced at all, according to the ATF. At the same time, the number of ghost guns used in crimes nationwide has risen sharply — jumping 1,000% since 2016, though they still make up just 3% of all guns recovered by police. 

Denver Police data shows ghost guns are turning up more frequently in the Mile High City, too. Denver Police confiscated 166 guns without serial numbers last year during criminal investigations, and so far this year, police have confiscated 108. In 2019, Denver Police only confiscated 67 during criminal investigations. 

Now for the first time in 50 years, the ATF is changing its requirements for firearm serial numbers, in aims to crack down on ghost guns. The last time the ATF had a rule change like this was in the 1960s, when guns were first required to have serial numbers. 

In April, President Joe Biden announced new regulations that will treat ghost guns — which can be made from parts bought online or with 3D printers — like any other firearms sold in the U.S.  

The new rules will require gun parts sold online to have serial numbers. 

"This allows us, ATF, to track these firearms when they're covering a crime scene and give that information back to a police department so they can have a lead or someplace to start an investigation involving a crime with that firearm," said Special Agent in Charge David Booth with ATF's Denver Division. "In this state, if you if you sell a firearm, you're required to go through a dealer. So, if you make a (privately made firearm) and you want to sell it to me, you have to take it to a dealer now and the dealer has to mark it and conduct a background check on me. So now, the firearm is marked or serialized and therefore if anything I do with it or it gets stolen, the police can trace it."

Denver Deputy City Attorney Kerry Tipper says earlier this year, the Denver city council passed an ordinance similar to the new federal rules about to go into effect. 

"What our focus has been in Denver is ensuring that we're doing everything we can to get dangerous guns off the streets," Tipper said. "(The ordinance) was really a first of its kind here in the state of Colorado, trying to get out ahead of this issue, and was to make clear that these guns, possession of these ghost guns, is an unlawful possession."

Asked if that ordinance has started to make a difference so far, Tipper said, "it's pretty early. We're roughly, seven, eight months into the new ordinance. So, we are looking forward to kind of looking at that data and seeing what impact it has had. But I can say, seeing that other municipalities are looking at this and that ATF is looking at it is a validation that this is an issue that Denver was out ahead of most other most other local governments on."

In the meantime, Booth says the federal changes may have a few speeds bumps once they go into effect on August 24. 

"The one problem is gun shops don't generally put serial numbers on things. So one of the snags in this is where do I go to put a serial number on this firearm," Booth said. "There's no set up serializing place for everybody to go to, or there's there's no set, as far as I know, there's no advice on that part yet."

But he says even as the kinks are being worked out, the changes have a lot of potential. 

"I don't know that if there's going to be any law that's going to keep bad people from getting firearms. They're always going to be able to, but I do think this is just a small step in making it a little more difficult, by making it be required to be marked, to be serialized, therefore able to be traced by the by police departments," Booth said. "So, I'm hoping that will deter some people."

Several states, including Montana, Nebraska, and Arizona, have filed suit to try to stop the rules from going into effect. 

As CBS News Investigates reported Wednesday, several online retailers of gun parts are scrambling to sell their unserialized parts before the rules change. 

The sites include companies like 80-lower.com, which urges visitors to "grab your freedom while you can" and links to product listings of AR-15 receivers. A similar site, 80percentarms.com, promises to continue shipping ghost gun parts until the day the rule begins. Representatives from 80-lower.com and 80percentarms.com didn't respond to CBS News' request for comment.  

Meanwhile, Booth says his division has been working to train local police officers in the metro area to better understand these privately made guns. 

He says the ATF held a training in late July in Lakewood, which saw more than 200 attendees from more than 30 law enforcement agencies across the state.

The main topics of instruction included: firearm manufacturing, identification and 3D printing of Glock conversion devices and silencers, the Crime Gun Intelligence Center; National Integrated Ballistic Information Network and Trace submissions, and a federal law overview of privately made firearms.