The U.S. Justice Department has launched a task force to stop the proliferation of machine guns because of a rapid increase in illegal conversion devices.
Even though fully automatic weapons have been banned for decades, criminals have found ways to use 3D printers to manufacture the Lego-sized devices often called “Glock switches” or auto sears. If one of these devices is installed on a semi-automatic handgun or rifle, the weapon can fire multiple rounds with one pull of the trigger.
A recent report by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) found a 570% increase in seizures of machine gun conversion devices.
ATF seized 5,454 machine gun conversion devices from 2017 to 2021, a 570% increase in devices seized over the previous five years.
Mass Shootings and Deaths
The appearance of so many converted, fully automatic weapons has resulted in bloodshed and grieving families.
In Detroit, rapid busts or gunfire could be heard on a home security camera as people scattered from a block party in July. When it was over, 21 people were shot. Two people died.
"I saw them being lifted away. It was just madness," a neighbor, Dondre Knight, told a reporter at WXYZ-TV after the shooting.
In Cincinnati, 11-year-old Dominic Davis was killed after someone in a dark sedan fired 22 shots into a crowd last November.
"Will this ever stop?" said Dominic’s father, Issac Davis, during a news conference about the shooting. "How many people have to bury their kids, their babies, their loved ones?"
At least two police officers, Brackenridge, Pennsylvania Police Chief Justin McIntire and Houston Officer William “Bill” Jeffrey, were also killed during shootings involving converted guns.
In Arizona, a suspect in a hit-and-run crash with a converted, fully automatic weapon opened fire on a Glendale police officer last year. Investigators determined the man got off 12 rounds before the officer returned fire, killing the man.
“It's scary,” Phoenix ATF Special Agent in Charge Brendan Iber told ABC15. He said an illegally converted Glock handgun can fire as many as 30 rounds in 2.3 seconds.
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“You have no control over where that's going, and so it's more of a spray,” he said. “The general public is caught up in it, wherever it is.”
Getting machine gun conversion devices off the streets is the AFT’s top priority, according to Iber.
“Those devices, in and of themselves, just those little pieces of plastic or metal that you have, are considered a machine gun, so just the basic possession of that, not attached to a firearm, is illegal,” Iber said. The crime is punishable by up to 10 years in prison.
The ATF has been training local police agencies to identify these devices, which may otherwise go unnoticed because they are so small and often black.
“Glock switches” are not manufactured by Glock, but they were designed specifically to fit like a button on the slide rear of Glock handguns.
A drop-in auto sear fits inside the housing of a rifle, so it’s hard to differentiate from an unmodified firearm.
3D Printing Machine Guns
Federal agents are now finding criminals manufacturing large quantities of switches and auto sears from home. All that’s needed is a downloaded file from the internet and a 3D printer that costs a few hundred dollars.
“So as long as you have the filament and the CAD drawings in the printer, you can print as many as you want,” Iber said. He added one device takes about 30 minutes to 3D print.
According to a federal court indictment from July, federal agents allege a northern Arizona man manufactured 1000 machine gun conversion devices using a 3-D printer over a 14-month period. He was one of 10 people listed on the indictment for conspiracy to possess machine guns. In another court filing, prosecutors said all the defendants were members of a motorcycle club.
ATF agents are also concerned about criminals going undetected as they create switches and auto sears for free on public 3D printers, especially in public libraries. Several Valley libraries have “maker spaces” where library cardholders have direct access to the printers.
ABC15 Investigator Melissa Blasius went to the Chandler Main Library to see the process firsthand. To access the Makery, she obtained a library card, watched training videos, and signed a waiver, which said she would not create a dangerous weapon. She booked a 3.5-hour appointment on the library’s website. Arriving like any other patron, she was briefly greeted by a library staffer and was directed to the room with the 3D printer. No one asked questions about what would be printed, checked the files used, nor entered the room while the printing was in progress.
ABC15 did not actually print a machine gun conversion device because it would have been illegal. Instead, Blasius printed a gun-shaped toy, which shoots rubber bands.
Agent Iber says the ATF is starting to train librarians and other managers of public 3D printers as crimefighting partners. The first training in the Valley took place four days after ABC15’s 3D library printing test.
“We need the news media to push this out, to make awareness of it,” Iber said.
He hopes that the librarians and others can learn what “Glock switches” and auto sears look like and know who to call if something seems suspicious.
“So the librarians and these school administrators or wherever these three printers are, can see what's being printed,” Iber said, “Maybe get information to pass along to state, local, and federal law enforcement once they see these things being manufactured.”
The librarian training is part of a bigger effort announced by the U.S. Department of Justice in early September to find ways to prevent people from 3D printing illegal machine gun converters.
“We need to engage software developers, technology experts and leaders in the 3D printing industry to identify solutions in this fight,” said U.S. Deputy Attorney General Lisa Monaco.
ATF Director Steve Dettelbach added, “We cannot let this great technology's misuse spoil things for all of those who have worked so hard to develop it.”
Libraries Respond
After completing the 3D rubber-band gun project, ABC15 reached out to a spokesman for the Chandler Public Library to ask about safeguards.
Chandler Communications Director Matthew Burdick said they “don’t want resources to be abused” or “used in a manner that could bring harm to people.”
According to the city of Chandler, library administration is reviewing its procedures related to 3D printing and gun regulations and will make any changes recommended by the Chandler Police Department to ensure full compliance with local, state and federal laws.
Burdick added the Chandler Police Department planned to reach out to its ATF liaison about the issue.
The Mesa Public Library also has 3D printers for hands-on use by patrons.
“We are aware of the proliferation of machine gun conversion devices (MCD) and the use of 3D printers to manufacture them,” said Mesa Communications Director Ana Pereira. “We have been communicating with the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) about this issue and coordinating additional training for library employees.”
Pereira added the priority is to provide a safe space for creators to “tinker, learn, and collaborate,” and they take every precaution they can.
Two other Vally cities, Phoenix and Glendale, have 3D printers in libraries for customers. But those customers do not have hands-on access. People must submit their 3D files to the library and can pick up the finished product.
“Our policy has been in place since we began offering 3D printing services in 2017,” said Dawn Ferro, Glendale’s interim chief librarian. “It is designed to increase the longevity of the machines by ensuring only trained personnel operate them and to also minimize material waste.”
In Phoenix, “Our practice of designating only library staff will have hands-on access to operate our 3D printers ensures that we are able to manage a limited resource, safeguard delicate and complex equipment, and maintain accessibility effectively and appropriately to a service that is in high demand,” said Lee Franklin, the community relations director for Phoenix Public Library.
Staff at both Glendale and Phoenix libraries said they have not encountered anyone trying to print illegal or inappropriate items.
You can reach ABC15 Senior Investigator Melissa Blasius by email at melissa.blasius@abc15.com or call 602-803-2506. Follow her on X (formerly Twitter) @MelissaBlasius or Facebook.
