Federal agents uncovered what appears to be a hidden workshop for manufacturing machine guns at a residence in Miami Gardens, Florida, on Wednesday, following the execution of a search warrant that led to the arrest of a 20-year-old man.
As reported by El Nuevo Herald, the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) agents targeted the property located in the 3900 block of NW 173rd Terrace after tracing several shipments from China to that address. These shipments contained conversion devices that transform semiautomatic firearms into fully automatic ones.
The operation was made possible by the efforts of an undercover agent who arranged to collect three homemade guns fitted with these devices, facilitating the acquisition of a judicial warrant.
Lance Ricardo Dwyer, who resides at the home, was apprehended on federal charges related to the illegal transfer or possession of machine guns.
Inside the residence, authorities discovered a bag containing three homemade firearms—two with conversion devices installed and one disassembled—several AR-15-style plastic weapons, a Glock-style pistol with a conversion device, four additional uninstalled devices, a 3D-printed gun, and two Springfield firearms.
However, the most startling discovery was a fully equipped setup for weapon manufacturing described in the complaint: "an oven, firearm manufacturing templates, clay molds, metal shavings, and a tool made of the same material as the metal conversion devices."
In the backyard, investigators found several workstations and a shooting test device specifically designed to "decrease the likelihood of shots being detected by ShotSpotter technology," the gunshot detection system operational in Miami Gardens that notifies police in about a minute.
This detail suggests a significant level of premeditation: the young suspect had allegedly developed a technical solution to avoid local police surveillance while building and testing illegal weapons.
Under U.S. federal law, a conversion device is classified as a machine gun in its own right, even if it is not installed on any firearm. Additionally, Florida has state laws prohibiting devices that alter firing rates to mimic automatic fire.
The incident is not isolated in the area. In June 2025, the ATF's Operation Showdown in South Florida resulted in 31 arrests and the seizure of 80 firearms, including automatic weapons and conversion devices, along with approximately 10 kilograms of illegal drugs.
Dwyer remains in custody and is being represented by a federal public defender, who did not respond to requests for comment from the Miami Herald.
His formal court appearance for the reading of charges is scheduled for August 27.
Understanding Machine Gun Manufacturing Laws in Florida
What are the legal implications of possessing conversion devices in Florida?
In Florida, possessing conversion devices that transform semiautomatic weapons into automatic ones is illegal. These devices are considered machine guns under federal law, regardless of whether they are installed on firearms.
How does the ShotSpotter system work in Miami Gardens?
The ShotSpotter system uses acoustic sensors to detect gunshots in real-time and alerts law enforcement within approximately a minute, helping them respond quickly to gunfire incidents.
What was the outcome of the ATF's Operation Showdown in South Florida?
Operation Showdown led to 31 arrests and the seizure of 80 firearms, including machine guns and conversion devices, as well as around 10 kilograms of illegal drugs.