ST. LOUIS – An alarming trend for authorities is the deadly conversion devices they’re seeing more of on the streets.

Agents recently arrested eight people in Cape Girardeau on charges of making machine guns.

“In 2022, ATF saw about a 500% increase in these types of aftermarket devices,” said Assistant Special Agent in Charge Brent Beavers, Bureau of Alcohol, Tobacco, Firearms and Explosives. “It’s really important to say that these are devices not made by the firearms manufacturers. They’re made with 3D printers or purchased overseas from China.”

Glock switches and aftermarket firearm parts have been seized by police over the past few years, and the number has been rising.

In 2019, St. Louis police seized one such part. This past year, authorities seized 27 parts in the city.

St. Louis Interim Police Chief Michael Sack said the department has already seized three thus far in 2023.

ShotSpotter, the citywide acoustic system that tracks the sounds of gunfire and fireworks, has seen a dramatic jump from year-to-year. In 2021, ShotSpotter captured 66 incidents of full-auto fire. This past year, it recorded 339 separate events of full-auto fire.

ATF agents, St. Louis police officers, and U.S. attorneys are joining forces to show the public these illegal devices.

“We will use every statute, every punishing provision, and every sentencing enhancement that we have available to us, should someone chose to possess or use one of these conversion devices,” said U.S. Attorney Sayler Fleming.

Anyone caught with such a device faces a minimum 30-year federal prison sentence, in addition to other charges.

If you have seen someone with these devices, you’re encouraged to contact St. Louis police, ATF, or the U.S. Attorney’s Office.