How gun accessories called bump stocks ended up before the U.S. Supreme Court

When gun accessories known as bump stocks first hit the market more than a decade ago, the U.S. government initially concluded that the devices did not violate federal law, despite the fact that semi-automatic weapons could spray bullets at the rapid rate of fire of a machine gun.

That changed after a gunman with bump stock-equipped rifles killed 60 people and injured hundreds more at a music festival in Las Vegas in 2017. It was the deadliest mass shooting in modern U.S. history.

Now a federal ban on bump stocks, imposed under then-President Donald Trump, is before the U.S. Supreme Court, which heard arguments Wednesday in a case testing the limits of the government’s ability to regulate guns in an era of mass shootings.

Here’s what you need to know about the case:

Bump stocks are accessories that replace the butt of a rifle that is pressed against the shoulder. When a person fires a semi-automatic weapon equipped with a bump stock, it uses the gun’s recoil energy to quickly and repeatedly bump the trigger against the shooter’s index finger.

This allows the weapon to fire dozens of bullets in a matter of seconds.

Bump stocks were invented in the early 2000s following the passage of a 1994 ban on assault weapons. The federal government approved the sale of bump stocks in 2010 after the Bureau of Alcohol, Tobacco and Firearms and Explosives concluded that guns equipped with these devices should not be considered illegal machine guns under federal law.

According to court documents, there were more than 520,000 bump stocks in circulation by the time Washington reversed course and imposed a ban that took effect in 2019.

More than 22,000 people were attending a country music festival in Las Vegas on October 1, 2017, when a gunman opened fire on the crowd from the window of his high-rise hotel room.

It was the worst mass shooting in modern American history, killing 60 people and injuring more than 850.

Authorities found an arsenal of 23 assault rifles in the gunman’s hotel room, including 14 weapons equipped with bump stocks. Investigators later concluded that the gunman, who committed suicide before police reached his room, fired more than 1,000 shots in just 11 minutes.

In the aftermath of the shootings, the ATF reconsidered whether bump stocks could be legally sold and repossessed. With support from Trump, the agency ordered a ban on the devices in 2018, arguing they turned rifles into illegal machine guns.

Owners of Bump shares were given until March 2019 to surrender or destroy them.

A group called the New Civil Liberties Alliance has filed a lawsuit on behalf of Michael Cargill, a gun store owner in Texas, challenging the bump stock ban.

According to court records, Cargill purchased two bump stocks in 2018 and then surrendered them once the federal ban took effect.

The case does not directly address gun owners’ Second Amendment rights. Instead, Cargill’s lawyers argue that the ATF has exceeded its authority by banning bump stocks. Mark Chenoweth, president of the New Civil Liberties Alliance, says his group would not have filed a lawsuit if Congress had banned them by law.

The Supreme Court took up the case after lower federal courts issued conflicting rulings on whether the ATF could ban bump stocks.

The ban survived challenges before the Cincinnati-based 6th U.S. Circuit Court of Appeals, the Denver-based 10th Circuit and the federal circuit court in Washington.

But the 5th U.S. Circuit Court of Appeals, based in New Orleans, struck down the ban on bump stocks last year when it ruled in the Texas case. The court’s majority in the 13-3 decision found that “a plain reading of the statutory language” showed that weapons equipped with bump stocks could not be regulated as machine guns.

The Supreme Court decided to hear the case last November.


Bynum reported from Savannah, Georgia.