A row of handguns are displayed at the Glock Inc. booth at the 2024 Special Operations Forces Week conference in Tampa, Fla. The company has become the target of mounting lawsuits from cities and states accusing it of failing to prevent illegal modifications of its firearms. (Luke Sharrett/Getty Images)
More states are enacting bans on “Glock switches,” small devices about the size of a U.S. quarter that can turn semiautomatic firearms into fully automatic weapons capable of firing up to 1,200 rounds per minute.
Gun conversion devices have become a rare point of bipartisan agreement on gun policy. Although firearm regulations often face pushback in Republican-led states, growing support from local law enforcement officials has helped these bans gain traction.
Last month, Alabama Gov. Kay Ivey, a Republican, signed into law a bill that made Alabama the 26th state to outlaw gun conversion devices, also known as auto sears. A sear is the part of the gun that holds the hammer or firing pin back until the trigger is pulled.
“While there is a federal ban on these gun conversion devices, we needed a way to empower our own law enforcement here in Alabama to get these illegal and extremely dangerous Glock switches off our streets,” Ivey said in a statement after signing the bill into law.
These devices, which can be 3D printed or bought online for as little as $20, have become closely associated with Glock handguns, which are often cited as some of the easiest to modify.
Georgia-based Glock Inc. doesn’t manufacture, market or sell the devices, but the brand has become synonymous with them, fueled in part by frequent use of the term “Glock switch” in some genres of music and on social media platforms.
The growing use of these devices in crimes — including mass shootings — has prompted lawsuits from several cities and states accusing Glock of failing to prevent illegal modifications and contributing to public safety risks.
The company did not respond to Stateline’s multiple requests for comment.
New Mexico Gov. Michelle Lujan Grisham, a Democrat, signed an auto sear ban into law in February as part of a broader public safety package. New Jersey could become the 27th state to enact a ban, after its General Assembly approved the measure in late March.
Other states — including Virginia and deeply conservative Mississippi — also have recently enacted bans. In GOP-led Tennessee, lawmakers are considering a similar measure, but the bill is still in committee and is unlikely to pass before the legislature adjourns on April 25.
“It’s a big deal to talk about places like Alabama, Mississippi, Virginia, Indiana putting these laws on their books,” Monisha Henley, the senior vice president for governmental affairs at the gun control advocacy group Everytown for Gun Safety, told Stateline. “There is a general consensus that we don’t want a switch or device or auto sear to be able to attach to a firearm and turn into a weapon or war.”
Recovered at crime scenes
The bans on auto sears are a response to a sharp nationwide increase in the number of modified firearms being recovered at crime scenes.
In 2023, law enforcement agencies recovered 4,530 machine gun conversion devices, or auto sears, at crime scenes across the country, according to the latest annual data from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, commonly known as the ATF.
The number of these devices recovered and traced by the bureau, a process that involves tracking a firearm or device back to its first point of sale or distribution, rose from 658 in 2019 to 5,816 in 2023 — a 784% increase, according to a recent report. That total includes recoveries from all 50 states as well as U.S. territories, including Puerto Rico, the U.S. Virgin Islands, Guam and the Northern Mariana Islands.
Between 2019 and 2023, conversion devices made up nearly 13% of all privately made firearms recovered by police and traced by the bureau — 11,088 out of 88,425 total.
Machine guns and conversion devices have been heavily restricted under federal law since 1934. While civilians can legally own machine guns made before 1986, those firearms must be registered in the National Firearms Registration and Transfer Record. Newer machine guns and conversion devices are generally illegal.
There are exceptions for licensed dealers and manufacturers producing them for military or law enforcement use. Possession of an unregistered device carries a penalty of up to 10 years in prison and/or a $250,000 fine.
The White House Office of Gun Violence Prevention, created by former President Joe Biden in 2023, quietly disappeared from the web on Jan. 21. Its website now returns a 404 error.
Just days before President Donald Trump’s inauguration, a task force within the office delivered a list of strategies aimed at cracking down on machine gun conversion devices.
Trump, who campaigned on loosening gun regulations, signed an executive order in February directing the U.S. Department of Justice to review all federal rules and guidance for potential infringements on Second Amendment rights, including those issued by the shuttered Office of Gun Violence Prevention.
In early April, U.S. Attorney General Pamela Bondi announced the creation of the Second Amendment Enforcement Task Force within the Justice Department. The announcement came soon after the rollback of the ATF’s “zero tolerance” policy, which previously required the agency to revoke the licenses of firearms dealers found to have willfully committed serious violations, such as selling guns without background checks or falsifying sales records.
Under the Biden administration, the Justice Department also established a separate task force, known as the ANTI-MCD Committee, to coordinate efforts and provide guidance on reducing the spread of machine gun conversion devices. Federal restrictions on machine guns and gun conversion devices remain in effect for now, but could change under the Trump administration.
Some gun rights groups argue state-level auto sear bans are unnecessary because the devices are already illegal under federal law.
“The overwhelming majority of gun owners are law-abiding citizens and are not just going to illegally produce or purchase auto sears,” Chris Stone, the director of state affairs for Gun Owners of America, told Stateline. “When you make it doubly illegal, it’s not stopping any criminals who are purchasing auto sears on the black market.”
Alabama and New Mexico
Alabama’s ban on auto sears comes in the wake of a mass shooting in Birmingham last September in which the devices were used. The shooting left four people dead, and 17 others injured.
The new law, which was sponsored in the Senate by Republican state Sen. Will Barfoot, makes it a felony to possess or sell any combination of parts intended to create an auto sear. Violators could face up to 10 years in prison and a $15,000 fine.
“This wasn’t about infringing on people’s gun rights. This was about making our community safer for everyone,” Democratic state Rep. Phil Ensler, who collaborated with Barfoot on the bill, told Stateline. Ensler also pushed for an auto sear ban during the past two legislative sessions.
The legislation exempts law enforcement and individuals who register their firearms with the National Firearms Registration and Transfer Record.
This wasn’t about infringing on people’s gun rights. This was about making our community safer for everyone.
– Democratic Alabama state Rep. Phil Ensler
According to the federal Centers for Disease Control and Prevention, there were 1,292 gun-related deaths in Alabama in 2023 — the latest year for which data is available. Alabama had the fourth-highest gun death rate in the nation at 25.3 deaths per 100,000 residents. The District of Columbia, Mississippi and Louisiana had higher rates that year.
New Mexico saw 530 gun deaths in 2023, placing it just behind Alabama with the fifth-highest gun death rate at 25.1 deaths per 100,000 residents.
Las Cruces, New Mexico, Police Chief Jeremy Story has expressed strong support for the new auto sear ban, which makes possession of a conversion device punishable by up to three years in prison and a $5,000 fine. Story also raised concern over the rise in juvenile crime, particularly the increasing use of gun conversion devices by teenagers.
Supporters in both Alabama and New Mexico argue that making possession of the devices a state offense allows local authorities to prosecute cases without relying on the limited resources of the federal court system.
“If this were not a state law … it’s completely unenforceable,” Ben Baker, the senior public safety adviser in the New Mexico governor’s office, told Stateline. “The federal government simply doesn’t have the resources, nor do they generally prosecute juvenile offenders,” said Baker, who has nearly 30 years of law enforcement experience.
Lawsuits against Glock
Several states and cities across the United States are taking legal and legislative action against Glock.
Lawsuits filed by Maryland, Minnesota, New Jersey and the cities of Baltimore and Chicago argue that Glock has long known about the widespread use of illegal auto sears but has failed to redesign its firearms to prevent these modifications.
In a court filing requesting the dismissal of Chicago’s lawsuit, Glock argued it should not be held responsible for illegal modifications made by third parties.
Beyond the courtroom, some states are weighing measures to prohibit the sale of firearms that can be easily modified with auto sears.
In California, such a bill has already passed out of the Assembly Judiciary Committee. A similar bill in New York has stalled in a Senate committee since January. Both states’ legislatures remain in session until September and June, respectively, leaving time for the proposals to advance further.
Maryland lawmakers also considered a similar measure this year, but the bill failed to make it out of a House committee before the legislature adjourned in early April.
Meanwhile, New York Gov. Kathy Hochul, a Democrat, signed a bill into law in early April that added “pistol converters,” or auto sears, to the state’s definition of rapid-fire modification devices. Possession of these devices already carried strict penalties.
Stateline reporter Amanda Hernández can be reached at ahernandez@stateline.org.