Kristopher Ervin, Machinegun Device Trafficking, Jacksonville FL, 2023

JACKSONVILLE, FL – A brazen scheme to turn legal AR-15 rifles into illegal machineguns has landed two men in federal prison. Kristopher Justinboyer Ervin, 43, of Orange Park, and Matthew Raymond Hoover, 39, of Wisconsin, were sentenced Friday to five years and eight months each after being convicted by a federal jury in April. Ervin also faces a $68,000 forfeiture order related to financial crimes stemming from the operation.

The ATF began investigating Ervin in January 2021 after his bank flagged suspicious activity – specifically, what employees believed was trafficking in machinegun conversion devices. The investigation quickly revealed a sophisticated online business selling these devices, deceptively marketed as “Auto Key Cards.” Ervin attempted to disguise the true nature of the cards, referring to them as “pen holders,” “novelties,” and even “political sculptures” – a pathetic attempt to evade law enforcement. He was shipping dozens of these cards weekly from an Orange Park post office.

These weren’t harmless trinkets. ATF firearms enforcement officers were able to extract the components of a “lightning link” from an Auto Key Card using a standard Dremel tool in under an hour. Once installed in a standard AR-15, the device converted the semi-automatic rifle into a fully automatic machinegun – a clear violation of federal law. The evidence uncovered at trial showed the conspiracy involved at least 6,600 individual lightning links, a staggering number of illegally modified weapons potentially flooding the streets.

Hoover, operating a YouTube channel called CRS Firearms, played a key role in boosting Ervin’s sales. His videos brazenly demonstrated how to extract the lightning link from the Auto Key Card, urging viewers to “scratch your full auto itch” and then discard the evidence. He even suggested the device could be used and then disposed of, ensuring “no one’s the wiser.” Multiple purchasers testified they were directly influenced by Hoover’s videos and intended to illegally modify their firearms. Ervin rewarded Hoover’s marketing efforts with cash sent through the mail and, in one instance, a luxury Louis Vuitton purse.

A search of Ervin’s home in March 2021 uncovered Auto Key Cards containing etchings for over 1,500 lightning links. The operation was clearly large-scale and motivated by profit. The sentencing, handed down by U.S. District Judge Marcia Morales Howard, sends a clear message that such blatant disregard for firearm laws will not be tolerated. The case was prosecuted by Assistant U.S. Attorneys Laura Cofer Taylor and David B. Mesrobian, with asset forfeiture handled by Assistant U.S. Attorney Mai Tran.

The investigation involved a collaborative effort from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), the U.S. Postal Inspection Service (USPIS), and the Internal Revenue Service – Criminal Investigation. ATF’s Jacksonville Field Office led the charge, demonstrating a dedication to dismantling dangerous operations that put public safety at risk. This case underscores the growing threat of easily accessible, illegal firearm modifications and the need for continued vigilance from law enforcement.

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