Charges: Minneapolis man used 3D printers to build machine guns

A man is accused of using 3D printers to build ghost guns, including illegal machine guns, in his Minneapolis home. 

The U.S. Attorney's Office on Wednesday said in a news release Aaron Cato, 25, is charged with possession of machine guns. He made his first appearance in federal court on Wednesday. He was ordered to remain in detention pending further court proceedings. 

The charges stem from a controlled delivery of a package to Cato on Aug. 31 that contained 30 gun parts. U.S. Customs and Border Protection agents had intercepted the package, sent from Taiwan to Cato, and delivered it to his home. Inside the package were enough gun parts to create 10 auto sears, a device that turns a semi-automatic gun into a fully automatic gun, which is considered a machine gun under federal law and is illegal. 

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Investigators then searched Cato's home, where they found five handguns and two AR platform guns. Three of the handguns had auto sears and were privately made ghost guns, charges allege. Investigators also found four 3D printers and multiple 3D printed auto sears in his home, a news release said.