BUFFALO, N.Y. — Long-awaited civil action is moving forward nearly a year after a white supremacist murdered 10 Black people at a Buffalo Tops supermarket.

Attorney General Tish James, D-NY, Thursday filed a lawsuit in state Supreme Court.

"We are suing MEAN Arms manufacturer which sells gun parts and we are holding them responsible obviously for the carnage that resulted on that same day," James said.

The attorney general believes MEAN LLC is guilty of false practices, false advertising and violating the state law that bans high-capacity magazines on rifles for marketing and selling an easily removed and replaced magazine lock.

"The lock was not really a lock," she said. "It is easily detachable and that's exactly what this young man did. He detached this lock and replaced it with a high capacity magazine and then he used that weapon to kill 10 innocent people."

In his manifesto, the shooter said he was able to remove the lock within minutes and replace it with a 30-round magazine, where state law allows no more than 10. The lawsuit alleged MEAN not only provided step-by-step instructions on the packaging to remove the lock but online tutorials.

"They were specifically marketing that for New York state and California," attorney John Elmore said.

Elmore, who represents several of the victims’ families, said he expects to file a lawsuit in the near future and is looking at MEAN as well as a body armor manufacturer and social media platforms that may have radicalized the shooter.

"It gives us confidence that our allegations and intuition and legal research is correct and it gives us a lot more juice to know that the Attorney General's Office is doing the same thing that we're doing," he said.

Elmore said, at the beginning of May, the company stopped marketing to New York and added a disclaimer it would not ship the product to the state. However, James said one of her investigators still successfully purchased one after the change.

"Despite their advertising that they no longer shipped to the state of New York, that's just not the case at all. It's further evidence that they've engaged in false advertising," she said.

The attorney general said the state is seeking injunctive relief to stop the sale, shipment and distribution of the lock moving forward as well as monetary damages. She said, if successful, she intends to make sure at least some of those funds go toward helping the community in East Buffalo where the tragedy occurred.