The Connecticut Supreme Court gave the green light Thursday to a liability lawsuit against the makers of the AR-15 rifle Adam Lanza used to kill 20 children and six adults at Sandy Hook Elementary School in December 2012.

The parents of nine victims brought the suit in 2014, seeking damages against Remington Arms Co. LLC and daughter company Bushmaster Firearms International LLC, which made the rifle. They argued the companies bore responsibility for selling and aggressively marketing a “weapon of war” to the general public.