Baltimore Police Col. John “Jack” Herzog III estimated that he first heard in 2018 about privately made firearms without serial numbers known as ghost guns.

“I became extremely worried,” Herzog testified on Tuesday in Baltimore Circuit Court. “I was nervous they were going to fall into the hands of criminals.”

Ghost guns, attorneys for the city allege, led to a public safety and health crisis in Baltimore — as these weapons caused violence, destruction and death. And one store in Maryland, they assert, contributed to and profited from that catastrophe here more than the manufacturer and multiple other dealers combined.

Lawyers for the city began presenting their case against Hanover Armory, a gun shop in Anne Arundel County that they claim in a lawsuit helped fuel an influx of these untraceable firearms. Baltimore is seeking at least $30 million.

Hanover Armory denies any wrongdoing.

Baltimore filed the public nuisance and negligence lawsuit in 2022 and previously reached a settlement with Polymer80, one of the largest manufacturers of ghost gun parts and kits in the United States, for $1.2 million. The company has since gone out of business.

In his opening statement, James Hannaway, one of the city’s attorneys, described the crisis as preventable.

Hanover Armory opened in 2016 about 10 miles outside the city and developed, marketed and sold full-build kits, which the business touted as easy to assemble, Hannaway said.

They did not feature serial numbers. The store also did not conduct background checks. So the product, he said, attracted those who could not legally buy firearms, including gun traffickers, teens and domestic abusers.

“It is highly appealing for someone who wants to commit a crime but doesn’t want to get caught,” Hannaway said.

The city sent out subpoenas and received records that revealed that Hanover Armory sold 2,347 ghost gun products, he said. That’s almost four times more than Polymer80 and other dealers in the state — combined.

Hannaway said the city is not asserting that the store was the only or one of the biggest factors in the crisis — just more than a negligible one. Baltimore, he said, is seeking accountability.

Tim Rudd, one of Hanover Armory’s attorneys, argued that Baltimore had long experienced issues with gun violence before the store opened, and contested that there is evidence tying the business to wrongdoing.

Rudd said unfinished frames and receivers and build kits only made up a fraction of the store’s sales.

The Bureau of Alcohol, Tobacco, Firearms and Explosives regularly conducts inspections at the store, he said, and did so as recently as this year.

“Hanover Armory,” Rudd said in his opening statement, “is still a federally licensed firearms dealer.”

These products, he said, were also readily available on the internet.

Though the shop did not run background checks, Rudd said there is no evidence that other stores conducted business any differently. Employees would ask people for ID, he said, and turn away customers if they had reason to believe something was wrong.

Baltimore Police Commissioner Richard Worley even stated in a deposition that he had never heard of Hanover Armory, Rudd said.

Circuit Judge Shannon E. Avery is presiding over the trial, which could last two weeks.