At Indianapolis crime scenes, an increasing number of devices that turn semiautomatic guns into fully automatic firearms are popping up, causing concern among local police.

Here’s what to know about these devices and the concerning rise of them in local crime: 

A machine gun conversion device is an accessory that, when installed, allows semi-automatic guns to fire without repeatedly pulling the trigger. The accessories are defined as a machine gun under the National Firearms Act even when not installed.  

The devices give a handgun the ability to fire 31 rounds in 2.1 seconds, according to the Bureau of Alcohol, Tobacco, Firearms and Explosives.  

No. Though commonly referred to as a Glock switch, police stress that the gun manufacturer Glock does not make these accessories.

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Yes. Commonly referred to names for machine gun conversion devices, according to the ATF, include:

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Lt. Shane Foley of Indianapolis police said machine gun conversion devices are often 3D printed and then sold on the street. In August 2022, a Franklin man was federally charged with manufacturing machine guns after investigators said he was 3D printing firearms and Glock switches that he sold to an undercover agent. Switches also are shipped from overseas, Foley said. ATF filed a case earlier this year against a Dallas man who received 30 switches from Taiwan. Investigators intercepted the packages and an undercover agent made the delivery.

Police said because these devices, when attached, allow a gun to fire more rounds in a much shorter period of time, they make a firearm much more difficult to control.  

“Somebody might be aiming in one place, and the rounds might be going somewhere completely different because it becomes that much more difficult to manage,” said Foley.  

Contact Sarah Nelson at 317-503-7514 or sarah.nelson@indystar.com