(CNN) A federal judge rejected a challenge to the Trump administration's ban on bump-fire stocks Monday.

United States District Judge Dabney L. Friedrich ruled against the plaintiffs in two consolidated federal lawsuits challenging a nationwide ban on the devices and asking for an injunction to prevent the ban from going forward and being enforced.

Bump-fire stocks came under scrutiny following a deadly 2017 massacre in Las Vegas, in which a gunman rigged his weapons with the devices to kill 58 people and injure nearly 900. The Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) responded, in part, by reconsidering its definition of machine guns to include "bump-stock-type devices."

Bump stocks, also known by the brand name Slide Fire, modify rifles, turning them into automatic fire weapons . When the trigger on an automatic weapon is pulled once and held, the gun continues firing until the trigger is released.

The ATF had previously concluded bump-fire stocks were merely a gun accessory or firearm part, not subject to federal regulation. They were tightly regulated, but legal.

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