What to Know About the Dangerous Firearms Used in the Seattle Shooting

Shooting Involved Nearly Every Major Product Innovation the Gun Industry has Introduced to Make Firearms More Lethal or Easier to Obtain Outside Existing Gun Safety Laws

SEATTLE - As more details emerge from the deadly mass shooting at Seattle's Bite of Seattle festival, law enforcement has confirmed the attack involved multiple firearms emblematic of the gun industry's role in fueling America's gun violence crisis. The guns found at the scene include a Glock pistol illegally modified with a machine gun conversion device commonly called a "switch" and equipped with a 40-round magazine, a Polymer80 ghost gun equipped with a 33-round magazine, and an additional handgun.

Together, these weapons represent a dangerous convergence of emerging threats fueling gun violence: DIY machine guns, ghost guns, and large-capacity magazines.

"No family should have to fear that a community celebration will become a mass shooting because the gun industry continues to innovate toward deadlier weapons," said Justin Wagner, senior vice president of law and policy at Everytown for Gun Safety. "The tragic shooting at the Seattle Center demonstrates how our commonsense gun laws - like Washington's machine gun restrictions - are being undermined by DIY machine guns, while ghost guns, 3D printed parts, and high-capacity magazines continue to make shootings more lethal."

Washington has led the nation in confronting emerging threats like ghost guns and 3D-printed firearms, but policymakers must also address firearms that can be easily converted into illegal machine guns. The gun industry cannot continue to profit from designing products that make it easier to evade our laws while communities pay the price.

DIY Machine Guns are the Next Frontier of America's Gun Violence Crisis

The recovery of a Glock pistol modified with a machine gun conversion device highlights a rapidly growing threat: DIY machine guns that circumvent longstanding machine gun laws and make shootings more dangerous. Machine guns have long been prohibited under federal law because of their uniquely destructive power. Capable of firing dozens of rounds in seconds, they can dramatically increase the number of people injured or killed in a shooting and create extraordinary danger for victims, bystanders, and responding law enforcement officers.

Today, criminals are increasingly evading longstanding machine gun laws by using cheap, illegal conversion devices to transform semiautomatic pistols into fully automatic machine guns in minutes. These devices are small, inexpensive, easy to 3D print, and are appearing at crime scenes across the country with alarming frequency. Additionally, the modified Glock was equipped with a 40-round magazine, dramatically increasing the volume of fire that can be unleashed in seconds, reducing opportunities for victims to escape, increasing the number of potential casualties, and placing responding officers at even greater risk.

Ghost Guns Continue to Undermine Public Safety

Police also recovered a Polymer80 ghost gun equipped with a 33-round magazine. Polymer80 was once the country's largest manufacturer of ghost gun kits, that allowed people to build unserialized, untraceable firearms at home while bypassing the background check system. The company ultimately declared bankruptcy after years of litigation and regulatory action.

Washington has already enacted strong laws restricting ghost guns, demonstrating important leadership on this issue. However, ghost guns manufactured before those laws took effect, as well as firearms trafficked across state lines, continue to pose serious challenges for law enforcement because they lack serial numbers and cannot be traced through traditional investigative methods.

3D Printing Continues to Accelerate the Threat

While authorities have not indicated whether the machine gun conversion device recovered in Seattle was 3D printed, nationwide law enforcement agencies have increasingly warned that 3D printing is accelerating the spread of both ghost guns and machine gun conversion devices. Affordable consumer printers, widely available digital blueprints, and rapidly improving technology have made it easier than ever for individuals to manufacture these items outside of the marketplace.

Washington recognized this growing threat and addressed it by passing HB 2320 in March, which strengthened Washington's ghost gun law and addressed the growing threat of 3D-printed machinegun conversion devices, and untraceable, 3D-printed firearms. As technology continues to evolve, policymakers will need to ensure gun safety laws evolve alongside it.

Large-Capacity Magazines Increase the Deadliness of Shootings

Police recovered 33- and 40-round magazines with the Polymer80 ghost gun and the modified Glock, respectively. Large-capacity magazines allow shooters to fire substantially more rounds without reloading, increasing the number of people who can be shot before victims have an opportunity to escape or intervene. Washington law generally prohibits the sale of magazines capable of holding more than 10 rounds, but these devices continue to appear at crime scenes through illegal trafficking and existing inventories.

From 2016 to 2025, shootings with four or more people killed where assault weapons and/or firearms equipped with large-capacity magazines were used resulted in twice as many people killed and more than 13 times as many people nonfatally injured. Additionally, in that time period, all ten deadliest mass shootings involved a large-capacity magazine.

Industry Accountability

The Seattle shooting involved nearly every major product innovation the gun industry has introduced to make firearms more lethal or easier to obtain outside existing gun safety laws: a handgun easily converted into a machine gun, an unserialized Polymer80 ghost gun, and high-capacity magazines capable of holding 33 and 40 rounds.

The gun industry generates billions of dollars annually while continuing to market and profit from products that make shootings deadlier, allow firearms to be manufactured outside the legal system, and undermine longstanding public safety protections.

Manufacturers continue to prioritize products that are easier to modify into machine guns, easier to build without serial numbers, and capable of firing significantly more rounds without reloading. This is fueling our nation's gun violence crisis.