Families who lost loved ones in the 2012 Sandy Hook school massacre can proceed with their wrongful-death lawsuit against Bushmaster Firearms International, manufacturer of the AR-15 rifle used to kill 20 children and six adults, a Connecticut Superior Court judge ruled on Thursday. 

…Judge Barbara Bellis rejected arguments made by Bushmaster, a division of Remington Arms, and its co-defendants, who sought to have the lawsuit dismissed. 

Bushmaster argued immunity from liability under a U.S. law designed to shield gunmakers from lawsuits when their products are used to commit crimes…

Bellis did not directly address the immunity question. Instead, she rejected Bushmaster’s claim that because the law is federal, not state, the state Superior Court didn’t have jurisdiction over the case…

The judge’s ruling, if it withstands appeals, could open the door for future challenges to liability immunity for gunmakers and sellers.

The Sandy Hook families contend Bushmaster, its parent companies, the gun distributor and the retailer that sold the rifle are liable for supplying a weapon unfit for civilian use…