Fourteen spent cartridge casings from two handguns — one of them a “ghost gun, the other equipped with an illegal “switch” to enable automatic fire — were among the evidence collected by police as they investigated a gunfight that killed three people and injured at least four others Sunday at the annual Bite of Seattle food festival at Seattle Center.
The ghost gun, a Polymer80 9-mm handgun with an extended magazine, was taken from a 15-year-old boy when he was arrested at the scene, Seattle police Chief Shon Barnes said at a news conference Tuesday. Barnes noted the weapon lacks a serial number, making it harder to trace.
Ghost guns, he said, “are typically homemade and they are illegal.”
Also found the night of the shooting was a Springfield Armory Range Officer compact 9-mm handgun loaded with seven rounds in a standard magazine that police do not believe was fired Sunday evening, Barnes said. He didn't say where the gun was found.
Police have said Junior Semo, 19, was involved in the shooting and was one of three people killed. Investigators haven't confirmed which gun was his.
A third handgun — a Glock 45 9-mm pistol — was found by patrol officers on Monday during food vendor cleanup at Seattle Center, Barnes said. The gun was equipped with an extended magazine and a switch that modified it from a semiautomatic pistol to fully automatic, he said.
In other words, it could fire like a machine gun, though the illegal modification typically makes a handgun harder to control and accurately fire.
Though the weapons are still undergoing ballistic testing, Barnes said it doesn’t appear that any of the handguns had been reported stolen.
So what exactly are ghost guns, switches and extended magazines? And who can legally own a handgun and how do police know if they’ve been stolen?
Ghost guns
About a dozen years ago, modern “ghost guns” — made from firearms parts kits sold online or from parts created with 3D printers — became part of the vernacular to describe weapons without serial numbers.
They are “ghosts” because there is no way to trace their origins or determine who they belong to, said King County sheriff’s Sgt. James Belford, who leads his agency’s gun violence prevention unit and is not involved in the Seattle Center shooting investigation.
Though some are rudimentary, others “look like something that might have been manufactured at a legitimate manufacturing company but are actually not,” he said.
Trigger mechanisms, slides and gun barrels are all later attached to the grip to make it a functional firearm, Belford said.
Typically, if a ghost gun is designed to look like a Glock, for example, a magazine designed for that type of firearm would be needed for it to work.
Switches
Switches are pieces of plastic or metal fashioned to interfere with a gun’s sear pin, attaching to the end of a slide and easily modifying a semiautomatic handgun into one that can fire automatically with a single squeeze of the trigger.
Sometimes called "machinegun conversion devices," switches are illegal to buy, sell or possess and "pose an extraordinary threat to public safety, according to the Bureau of Alcohol, Firearms, Tobacco and Explosives. They can be made with 3D printers or illegally bought online.
While some of the metal switches have knobs on them that, in theory, allow either a single bullet to be fired or rotate for automatic fire, Belford said they rarely work, most often resulting in a spray of bullets.
When a switch is added to a handgun, “the firearm is going to tend to want to climb,” and the recoil from firing a fast barrage of rounds “lifts the barrel up and up and up,” making it much harder to aim and control, Belford said.
The illicit use of switches means there are a lot more fired casings at shooting scenes, often congregated together in clusters where each shooter fired from, he said.
Extended magazines
Extended magazines and drum magazines both fall into the category of “large capacity” magazines and the sale of new ones was made illegal in Washington in 2022. The law has faced legal challenges, but it’s still legal to own large-capacity magazines — defined in state law as any magazine capable of holding more than 10 rounds — that were in circulation before the law went into effect.
Extended magazines typically hold 25 rounds, though some hold more and others fewer rounds. The magazines extend below the grip of a handgun, Belford said. Meanwhile, drum magazines are circular and usually have a 50-round capacity, he said.
The ghost gun seized in the Seattle Center investigation had an extended magazine with capacity for 33 rounds, and 19 unfired rounds were recovered with the weapon, Barnes said. The Glock 45 had an extended magazine with a 40-round capacity, and 21 rounds were left over when it was found by police, he said at the Tuesday news conference.
The large capacity of rounds means more bullets can be fired without having to reload.
Youth and guns
Under state law, guns cannot be legally possessed by kids under the age of 18, people convicted of felonies, anyone arrested or convicted of a crime of domestic violence, subjects of domestic violence protection orders, and anyone court-ordered into involuntary mental health treatment for 14 days.
Firearms legally purchased and registered in Washington are entered into a statewide database, Belford said.
Serial numbers on guns recovered by police can be run through the database and alert them to whether a weapon has been reported stolen, Belford said. But if a gun is purchased in or stolen from another state, brought here and used in a shooting, “we’re not going to get a record of that,” he said.
Though Washington gun owners can register firearms purchased in another state, they aren’t legally required to do so. And until a couple years ago, gun owners weren’t required to report a lost or stolen gun to police, according to a Seattle Times analysis of recent firearm legislation. That changed with the passage of a 2024 law.
Belford’s unit, formed in 2023 and comprised of Belford and four detectives, arrests “a pretty even split” of adults and juveniles involved in shootings or found to be illegally in possession of firearms, he said.
Seattle Times staff reporter Shauna Sowersby contributed to this story.
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