BALTIMORE (AP) — The city of Baltimore filed a lawsuit against one of the largest manufacturers of “ghost gun” kits in the United States on Wednesday, the same day Maryland’s ban on the untraceable weapons went into effect, news outlets reported.

Mayor Brandon Scott said the suit was filed in Baltimore Circuit Court against Nevada-based Polymer80, which sells kits for customers to assemble themselves, and Hanover Armory, an Anne Arundel County gun store. The suit alleges that Polymer80 intentionally undermines federal and state firearms laws by designing, manufacturing, and providing kits and parts without serial numbers to buyers who do not undergo background checks.

“Takedowns are not enough. Legislation is not enough,” Scott said during a news conference. “We have to crack down on the companies that are profiting off of destruction and death in our communities.”

The new state law expands the definition of a firearm to include “an unfinished frame or receiver.” Anyone who sells or transfers a ghost gun faces up to five years in prison and a fine of up to $10,000. When a second phase of the law takes effect in March 2023, a person who possesses a ghost gun will face two years in prison and a fine of up to $10,000.

Polymer80 President and CEO Loran Kelley Jr. declined to comment to The Associated Press. A person who answered the phone at Hanover Armory declined to comment, news outlets reported. It’s unclear whether either business has been served.

The lawsuit was filed by the city’s affirmative litigation division, the Brady Center to Prevent Gun Violence and Sanford Heisler Sharp, a national public-interest law firm. It is similar to ones filed by the cities of Washington, D.C., and Los Angeles. While the suit doesn’t specify what damages it seeks, City Solicitor James Shea said officials are working on an estimate that would be “substantial.”

City police have said ghost guns have been used in an increasing number of shootings. No ghost guns were seized in the city until 2018, but last year police recovered 324, 14% of all firearms recovered, officials said. So far this year, ghost guns accounted for 19% of all guns seized. Ninety-one percent of ghost guns recovered by police in Baltimore from January 2020 until this April were Polymer80 guns, according to the complaint.

“Ghost guns are a devastating menace to the people of Baltimore,” Scott said. “This lawsuit shines a light on Polymer80 and individuals who routinely create a marketplace for deadly, untraceable weapons.”

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