The Bump Stock Ban Stemmed From a Horrific Mass Shooting

The ban on bump stocks overturned by the Supreme Court on Friday was a rarity in an era of deep division over gun violence: a restriction that won support from Democrats, Republicans and even the National Rifle Association.

Bump stocks are attachments that allow a semiautomatic rifle to fire faster. The effort to limit bump them, which former President Donald J. Trump put in place by executive order in 2018, gained support after a gunman killed 60 people at a concert in Las Vegas. It was the deadliest mass shooting in modern American history.

What happened in Las Vegas?

On the night of Oct. 1, 2017, a gunman who had smuggled rifles and reams of ammunition into his suite on the 32nd floor of a Las Vegas hotel opened fire. His target was a crowd attending the Route 91 Harvest country music festival.

The gunman killed 58 people and himself that night. Hundreds more concertgoers were injured in the frantic rush to escape the long, rapid-fire bursts of gunfire that rained down from the gunman’s room at the Mandalay Bay Resort. Two of the wounded later died.

How did bump stocks play a part?

About a dozen of the gunman’s rifles that were later found by investigators had been modified with devices known as bump stocks.

These accessories can cost as little as $99. They replace a rifle’s standard stock, which is the part held against the shoulder. The bump stock frees the weapon to slide back and forth rapidly, harnessing the energy from the kickback shooters feel when the weapon fires to make a semiautomatic rifle fire more like a machine gun.

The Las Vegas gunman was able to fire more than 1,000 rounds in about 11 minutes.

“You certainly don’t need bump stocks to have mass shootings,” said Adam Winkler, a law professor at the University of California, Los Angeles. “But what happened in Las Vegas was a whole other level.”

Ownership of fully automatic weapons, like machine guns, is strictly limited under federal law. But critics say bump stocks skirt the law by effectively turning semiautomatic rifles into automatic weapons, which are rarely seen outside of battlefields.

In a brief to the Supreme Court supporting the ban, the Giffords Law Center to Prevent Gun Violence quoted one gun manufacturer’s advertisement that declared as much: “Bumpfire stocks are the closest thing you can get to full auto and still be legal.”

A ban generated wide political agreement.

The immense tragedy of the Las Vegas shooting brought calls from unlikely political corners to ban, or at least restrict, bump stock devices. The Bureau of Alcohol, Tobacco, Firearms and Explosives under the Obama administration had considered such a ban, but decided it didn’t have the regulatory authority to do so on its own.

Within days of the shooting, the National Rifle Association endorsed stronger restrictions. Top Republican lawmakers said they would consider making them off limits. Then, a few months later, after another deadly mass shooting — at a high school in Parkland, Fla., where the shooter did not use a bump stock — President Trump also said he supported a ban.

The Trump administration enacted one in December 2018, with the A.T.F. issuing a new regulation that banned the devices.

It went into effect on March 26, 2019, and the A.T.F. urged anyone who owned a bump stock to turn it in to an A.T.F. office or to destroy it, posting detailed instructions on its website.

The government has estimated that roughly 520,000 bump stocks were produced between 2010 and 2017.

How did the ban get overturned?

One day before the regulation went into effect, Michael Cargill, the owner of a gun shop in Austin, Texas, walked into the city’s A.T.F. office and announced his lawsuit challenging the ban.

He was represented by the New Civil Liberties Alliance, a legal advocacy group that has pursued cases trying to limit the government’s administrative power.

The Supreme Court heard oral arguments in the case in February, and on Friday, the court’s six Republican-appointed justices issued a ruling that the A.T.F. had exceeded its authority in issuing the ban, knocking it down.

In a concurring opinion, Justice Samuel Alito said limits on bump stocks should come from lawmakers, rather than administrative agencies.

“There is a simple remedy,” he wrote, saying that Congress could change the law, and suggesting that it might have already if the A.T.F. hadn’t issued a ban. “Now that the situation is clear,” he wrote, “Congress can act.”