Sixteen states have filed a lawsuit against the Trump administration over its plan to permit the sale of forced-reset triggers (FRTs). The triggers are a type of firearm mechanism that allows a rifle shooter to fire at a much faster rate than a firearm equipped with a standard semi-automatic trigger.

Washington has joined 14 other states and the District of Columbia in challenging a Bureau of Alcohol, Tobacco, Firearms and Explosives plan to return seized “forced reset triggers,” a device the Washington attorney general’s office says allows novice shooters to “achieve the firepower of a military machine gun.