Department of Justice

United States Attorney Gregory J. Haanstad of the Eastern District of Wisconsin announced that on March 20, 2023, Senior United States District Judge William C. Griesbach sentenced Mitchell J. Guerrero (age: 30) to a total sentence of 46 months’ imprisonment and three years’ supervised release for manufacturing and trafficking 3D-printed firearms, commonly referred to as “ghost guns” because they lack serial numbers and thus are untraceable.

According to court records, in November 2021, investigators with the Brown County Drug Task Force searched Guerrero’s residence in Green Bay, Wisconsin, and located a 3D printing lab in his basement. Near the lab, investigators seized a fully functional 3D-printed plastic handgun, 3D-printed magazines and rounds, 3D-printed silencers, and a 3D-printed “sear” that could convert an AR-15 rifle into a fully automatic weapon. Investigators also located evidence that Guerrero was in the beginning stages of manufacturing a 3D-printed AR-15.

The 3D-printed plastic handgun was sent to the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) Firearms Technology Criminal Branch for a technical examination, where it successfully fired. The firearm also was subjected to a Transportation Safety Administration (TSA) metal detector. During the test, the firearm successfully went through TSA screening without setting off the alarm. This is the first known fully operational plastic firearm seized by ATF that has successfully passed through a TSA metal detector.

Investigators also discovered evidence that Guerrero offered to sell ghost guns and traded one firearm for methamphetamine. At the sentencing hearing, Judge Griesbach discussed the dangerousness of trafficking untraceable firearms and noted that this type of crime will not be tolerated.

This matter was investigated by ATF and the Brown County Drug Task Force. It was prosecuted by Assistant United States Attorney Alexander E. Duros.