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

A spokesman from Polymer80 did not respond to repeated requests for comment. A person who answered the phone at Hanover Armory would not answer questions. Lawyers for the city accuse Hanover Armory in the complaint of regularly selling Polymer80 gun kits in Maryland without determining whether customers are prohibited from owning a firearm.

The lawsuit, similar to ones filed by the District and Los Angeles, does not spell out how much the city is seeking in punitive and compensatory damages. City Solicitor James L. Shea said the amount would be “very substantial” and that officials are still working on an estimate. Shea said the amount will encapsulate the “societal problems that are created, down to cleaning up the mess that Polymer80 created here in the city.”

The legal action, which was taken on the same day a state law goes into effect that bans the sale, transfer and receipt of untraceable firearms, was filed by the city’s affirmative litigation division within the Department of Law, the Brady Center to Prevent Gun Violence and Sanford Heisler Sharp, a national public-interest law firm.

The lawsuit also comes days after an 18-year-old gunman killed 19 children and two teachers at an elementary school in Texas, a mass shooting that has again raised questions about the country’s gun-control laws and how to prevent gun violence.

The lawsuit alleges that Polymer80 intentionally undermines federal and state firearms laws by designing, manufacturing and providing ghost-gun kits and parts, which lack serial numbers — making them nearly impossible to trace — to people who do not undergo background checks.

“Polymer80’s primary market consists of those who want to evade law enforcement or who cannot obtain a gun from a [federal firearms licensee], including underage buyers, buyers with criminal convictions, and gun traffickers,” the lawsuit reads.

City officials said ghost guns, which are sold in parts and can be assembled at home, make up 19 percent of all the guns recovered so far this year by Baltimore police and that 91 percent of those seized ghost guns were manufactured by Polymer80. No ghost guns were recovered in 2018; three years later, the police department seized 352 ghost guns. In the first five months of 2022, there have been 187 recovered, authorities said, which outpaces last year’s rate.

According to the lawsuit, Baltimore police linked 32 of the 352 ghost guns recovered last year to a homicide or shooting. Dante Barkdale, an outreach worker with the Safe Streets Baltimore program and one of the more than 300 victims of gun violence last year, was shot nine times with an unserialized Polymer80 handgun, the lawsuit reads. Teens as young as 14 have been arrested for possession. Nearly a quarter of recovered ghost guns have been in the possession of individuals younger than 21, the legal age to possess a firearm in Maryland.

“I’ve said time and time and time again that firearms that do not have serial numbers and/or registration have no place in our city and, dare I say, in the United States of America,” Scott said. “It should not be easier for me to purchase a ghost gun than it is for me to buy my allergy medicine at CVS or go to buy a used car. If a young person can’t drink or buy alcohol from a liquor store, if they can’t rent a car, they shouldn’t be able to go online and buy a ghost gun.”

Under the new state law, the definition of a firearm is expanded to include “an unfinished frame or receiver.” A dealer can be charged with a crime and lose its license if, among other things, it “knowingly or willfully manufactured, offered to sell, or sold a handgun not on the handgun roster.”

Anyone who sells or transfers a ghost gun can face punishments of up to five years in prison and a fine up to $10,000. Beginning in March, when the second phase of the law takes effect, a person who possesses a ghost gun can face two years in prison and a fine up to $10,000.