Federal agents say the second sale arrived in a toaster pastry box. Fifty small conversion devices. Three hundred dollars. That works out to six bucks apiece for parts the law treats as machine guns the moment they exist.
The buyer was an undercover ATF agent. The seller, according to a Sept. 3 criminal complaint in the Middle District of Florida, was Emani Rey Justavino, 19, of Jacksonville. He is accused of illegally possessing machine guns and possessing firearms not registered in the National Firearms Registration and Transfer Record. Those are allegations. He is presumed innocent unless a court says otherwise.
The Times-Union reported he was detained Sept. 10 and that a conviction could carry up to 10 years.
How ATF says the buys went
The case did not start on a dark-web forum. An ATF task force officer saw someone tagged in the complaint as “J.B.J.” advertising “Glock switches” on Instagram. A confidential source reached that account and got pointed to another handle, “904hottshop.” Four printed devices for $200. Meet at a Gators Dockside in St. Johns County on Aug. 18.
Justavino showed up, phone records later tied to the seller’s number, but he did not have the parts on him. He sent the undercover pair to a nearby house. A person the complaint calls “Ray” handed over four devices in a clear plastic case. Agents say Justavino set the price and the pickup.
The next day the agent called again. Justavino allegedly said he had printed 50 overnight and had run low on material. They met on North Malibu Way. He got into the government car and passed over the pastry box with all 50 inside. The agent offered $400 for 16. The complaint says Justavino countered with the whole stack for $300. The agent paid with official funds.
Agents also say he tried to move a tan Glock 19 for $1,000, then backed off when the agent tried to haggle. He discussed other guns too. None of that has been proven at trial.
Why a loose part counts as a machine gun
A “Glock switch” is a machine-gun conversion device. Slip it onto certain semiautomatic pistols and one trigger pull can dump the magazine. The complaint cited in local coverage said a converted Glock can run on the order of 1,200 rounds a minute. Glock does not make these parts. They are aftermarket, usually printed or imported, and sold as “switches,” “chips,” or auto sears.
Federal law does not wait for the part to be installed. The National Firearms Act defines a machine gun to include any part “designed and intended” to convert a weapon into one. ATF’s position is that the device itself is a machine gun even in a drawer. New ones generally cannot be registered for civilian possession after the 1986 Hughes Amendment. Possessing or transferring them without a lawful exception is a felony. Florida has its own ban on top of that.
That is why the complaint talks about the National Firearms Registration and Transfer Record. These prints had no serial numbers and no paperwork. Under that statute, they did not need to be attached to a pistol to create the charge.
ATF’s Los Angeles field division said in a 2024 notice that agents had recovered more than 31,000 conversion devices in five years. Later tallies used by researchers put recoveries above 31,000 from 2019 through 2024. The parts are small. They ship. They print. That is the enforcement problem in one paragraph.
The price tells you the supply story
Four for $200 is $50 each. Fifty for $300 is $6 each. He allegedly printed the second batch overnight. That is not a boutique smuggling pipeline. That is a desktop printer and a file.
Greg Sanfilippo, a former counterintelligence officer now at Doyle Security Services, told News4JAX the files move on the dark web and the finished parts move after that. Investigators, he said, still have to chase customers, the chat apps, and the money. Instagram was the storefront in this complaint. That is a different kind of “dark.”
This pattern is not unique to Duval County. In 2023, a 19-year-old in Illinois, Zavien James Ross, took 27 months after selling 3D-printed Glock switches and an AR auto sear to undercover agents. In June 2026 a Texas City man, Jaleel Filer, drew 37 months after an undercover run that included a batch of more than 50 conversion devices. The ages change. The product and the buy-bust rhythm do not.
Glock has been redesigning slides and trigger bars on newer “V” models to make these plates harder to use. That does not pull existing pistols out of circulation, and it does not stop someone from printing parts for the older ones.
What the Jacksonville case actually proves so far
It proves ATF can still walk an Instagram ad into a recorded buy. It does not prove how many devices left that house before Aug. 18. Sanfilippo’s point about “hundreds of customers” is a lead, not a head count. The complaint describes two undercover purchases totaling 54 parts. Anything beyond that is work still on the desk.
The street fear is real enough without dressing it up. Converted pistols show up in gang shootings because they are cheap, concealable, and dump a magazine before a bystander can get off the sidewalk. That is why prosecutors charge the part as the gun. It is also why a 19-year-old with a printer and a pastry box can face the same statutory box as someone moving factory machine guns.
The next filings will matter more than the first headline: indictment versus complaint, detention versus release, and whether “Ray” or the Instagram accounts become separate cases. Until then, the record is a two-day sting, a $300 box, and a federal definition that has treated these devices as machine guns for years.