A trial over whether a gun shop bears responsibility for selling a weapon that was ultimately used to seriously injure two cops is under way in Wisconsin.

Milwaukee police officer Bryan Norberg and former officer Graham Kunisch accuse Badger Guns, a firearms store in West Milwaukee, of negligence for selling a Taurus handgun on May 4, 2009, to straw buyer Jacob Collins, who in turn gave it to Julius Burton, an 18-year-old with a criminal history, according to reports.

Both Collins and Burton got prison time after Burton allegedly used the firearm to shoot the officers June 9, 2009. Kunisch was struck in the face and lost his left eye.

The Brady Campaign to Prevent Gun Violence has filed a lawsuit against Badger Guns on behalf of the officers.

“Badger’s record of selling crime guns is worse than 99.9% of other dealers, and is significantly worse than some dealers among the worst 0.1%,” the complaint reads.

The nonprofit alleges that Badger has sold an average of more than 10 "crime guns" a week and accounts for two-thirds of all crime guns recovered in the state.

Norberg and Kunisch say that Badger knew or reasonably should have known that selling the .40 caliber handgun to Collins was illegal.

Collins and Burton entered the store together, Burton picked out which gun he wanted, and Collins even wrote that he was not the actual buyer of the weapon while completing a Firearms Transaction Board form, according to the complaint.

“Rather than terminate the sale and contact police about this unlawful straw purchase attempt, Badger Guns conspired with Collins to change his answer to claim falsely that he was the actual buyer of the gun,” it reads.

Attorney James Vogts, who is representing the store, could not be reached for comment, but he previously told the Milwaukee-Wisconsin Journal Sentinel that the owners observed measures to keep their guns out of the hands of criminals and that the allegations amounted to nothing more than a smear campaign.

Story continues

The Brady Campaign, though an advocate for gun control, clarifies that this particular lawsuit in no way challenges the second amendment, or responsible gun dealers.

NBC News points out that cases against gun dealers for negligently supplying criminals with firearms are usually settled out of court, but opening arguments took place Tuesday.

"I do not know of any other cases like it. I think this is a new theory," Janine Geske, a law professor at Marquette University and former Wisconsin Supreme Court justice, told the news site. "It's a new attempt to try to deal with the guns that come out of some of these gun stores."

The ultimate verdict could have implications for gun store operations across the country.

Throughout its history, the gun dealer has operated under several names: Badger Guns, Badger Outdoors, and Badger Guns & Ammo.

The U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives revoked owner Adam Allan’s license to sell firearms in 2011, resulting in the shop’s closing for a brief period, the Journal Sentinel reports.

Shortly after, his brother Mike Allan reopened another gun store at the same address named Brew City Shooter Supply.

The gun shop declined to comment when contacted by Yahoo News.

Related: