A man going by the moniker “Kem” claims to have made $21,000 from New York’s gun buyback program by 3D printing gun parts.

After seeing stories about similar schemes in other states, Kem decided to print gun parts, and drive them six hours to the state buyback event in Utica, New York, on Aug. 27.

“I 3D-printed a bunch of lower receivers and frames for different kinds of firearms,” Kem told WKTV-TV, a Utica NBC affiliate.

Once he had handed over his gun parts, a long haggling session ensued with the staff of New York Attorney General Letitia James.

The scheme paid off, to the tune of 42 gift cards, each worth $500, for a total take of $21,000.

Kem expressed to WKTV that his actions stemmed not just from the profit motive, but also from a desire to show up what he sees as misguided government policy.

“I’m sure handing over $21,000 in gift cards to some punk kid after getting a bunch of plastic junk was a rousing success. Gun buybacks are a fantastic way of showing, number one, that your policies don’t work, and, number two, you’re creating perverse demand,” Kem said.

The Attorney General’s office has since taken action to prevent similar schemes in the future.

“It’s shameful that this individual exploited a program that has successfully taken thousands of guns off the streets … one individual’s greedy behavior won’t tarnish our work to promote public safety. We have adjusted our policies to ensure that no one can exploit this program again,” the Attorney General’s office told WKTV.

At the Sept. 17 buyback in Camillus, New York, 3D printed and homemade “ghost guns” were not eligible to be turned in, whereas the Utica buyback had no such stipulations.

3D printed guns turned in at that event also had to be capable of safely firing multiple rounds.

On Twitter, Kem posted pictures of his parts and his spoils, and claimed to be the cause of the rule change.