A Utah man is facing up to 20 years in federal prison after a jury convicted him in Salt Lake City’s U.S. District Court on Wednesday of importing machine guns from China and selling them in the state at a steep markup.

After a four day trial, Gary Mark Hill, 42, was found guilty on one count of unlawfully engaging in the business of importing and dealing machine guns and one count of illegal possession and transfer of machine guns. The jury deliberated for less than two hours before returning the verdict against him.

“In this day and age, there are few transactions more dangerous than an anonymous and unregulated exchange of cash for machine guns,” U.S. Attorney John Huber said in a written statement Wednesday. “This intentional conduct showed a reckless disregard for our safety at its best, and certainly exposed Utah to risks that the community should not have to bear. The jury had little difficulty in holding the defendant accountable.”

The indictment against Hill states that he “knowingly” imported and dealt in firearms and machine-gun conversion devices for Glock guns without having paid the special occupational tax or having registered to do so as required by federal law.

The Salt Lake City man was caught after he sold multiple illegal machine gun conversion devices to three undercover Alcohol, Tobacco, Firearms and Explosives agents on Feb. 27, 2017, March 1, 2017 and March 8, 2017, according to the news release. A search warrant of his car and home resulted in 11 additional machine gun conversion devices.

Those conversion devices are considered machine guns under federal law “because they are parts designed solely and exclusively for the purpose of converting a semi-automatic handgun into a machine gun,” according to the U.S. Attorney’s Office.