The Supreme Court Just Made Future Mass Shootings Even Deadlier

Six years ago, a man opened the outer window of his Las Vegas hotel room, pointed a semiautomatic rifle at a nearby concert, and opened fire. In the roughly 10 minutes that followed, he sprayed more than one thousand rounds down at concertgoers. Sixty people died in the ensuing carnage, making it the single deadliest mass shooting in American history. Nearly 900 more people were injured, with just over 400 of them wounded by gunfire and shrapnel, and the rest suffering other injuries as people stampeded to safety.

What enabled such senseless slaughter? Investigators found that the gunman’s rifles were equipped with bump stocks, a device that modifies semiautomatic rifles to fire as rapidly as fully automatic ones. Bipartisan horror led to calls to ban bump stocks. The Trump administration, via the Bureau of Alcohol, Tobacco, Firearms, and Explosives, banned them the following year under a 1934 law that regulates machine guns.

The Supreme Court undid all of that on Friday and cleared the way for bump stocks to be sold again. In a 6–3 decision that fell along the usual lines, the court ruled that the devices were not covered by existing federal laws and signaled that new ones would be necessary.

“This case asks whether a bump stock—an accessory for a semiautomatic rifle that allows the shooter to rapidly reengage the trigger (and therefore achieve a high rate of fire)—converts the rifle into a ‘machinegun,’” Justice Clarence Thomas wrote for the court. “We hold that it does not and therefore affirm.”

In doing so, the court has made it more likely that future mass shootings will be deadlier than they already are. To reach their ruling, the court adopted a strained and artificial interpretation of the laws in question. Their arguments that Congress and the White House are actually to blame are not entirely convincing.

“The majority’s reading flies in the face of this Court’s standard tools of statutory interpretation,” Justice Sonia Sotomayor wrote in a dissent joined by Justices Elena Kagan and Ketanji Brown Jackson. “By casting aside the statute’s ordinary meaning both at the time of its enactment and today, the majority eviscerates Congress’s regulation of machineguns and enables gun users and manufacturers to circumvent federal law.”

The plaintiff, Michael Cargill, handed over his two bump stocks to the ATF after the ban in 2018 and then sued the agency to challenge its lawfulness. While this case involves firearms, it is not technically a Second Amendment case. The court instead considered whether the ATF rule went beyond what Congress had authorized. In 1934, lawmakers enacted the National Firearms Act, or NFA, to crack down on certain types of firearms that were commonly associated with crime at the time, such as short-barreled shotguns and machine guns.

That law, contrary to popular misconception, did not make it illegal for private citizens to own a machine gun. But the licensing and regulatory requirements make it so difficult that they are effectively beyond the reach of most Americans. The NFA defined a machine gun as “any weapon which shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger.” It also covers “any combination of parts” that could convert a semiautomatic firearm into a fully automatic one.

What counts as a “single function of the trigger”? First, it’s worth explaining how bump stocks actually work. When someone pulls the trigger of a commercially available AR-15 rifle, which is semiautomatic, the firearm’s internal mechanisms automatically replace a discharged round with a new one. The shooter must then pull the trigger additional times to fire each new round. A fully automatic rifle does not require a person to pull the trigger more than once. Instead, it will keep firing and replacing rounds until the gun’s magazine is empty, as long as the trigger is held.

Bump stocks turn a semiautomatic rifle into what is essentially a fully automatic rifle. A normal stock—the part you place against your shoulder—is typically solid and fixed. This allows for greater control when aiming and firing the gun, despite the recoil, which is absorbed by the person’s upper torso. A bump stock, on the other hand, has a sliding portion that allows for movement between the part that rests against one’s shoulder and the rest of the gun.

Simple physics takes over from there. When someone fires an AR-15 rifle that’s equipped with a bump stock, the recoil propels the gun into their shoulder and then back toward the shooter’s finger after each shot so that it can be fired continuously. All of this takes place in a fraction of a second. To see what it looks like in practice, compare the difference in this YouTube video when the gunman fires an AR-15 without a bump stock starting at 2:10, and when he fires it with a bump stock starting at 4:05. The shooter empties the entire magazine in only a few seconds.

That brings us back to the “single function of the trigger.” Thomas, writing for the majority, concluded that each time the recoiling gun touches the shooter’s finger, it counts as a new function. “A bump stock merely reduces the amount of time that elapses between separate ‘functions’ of the trigger,” he wrote. “The bump stock makes it easier for the shooter to move the firearm back toward his shoulder and thereby release pressure from the trigger and reset it. And, it helps the shooter press the trigger against his finger very quickly thereafter. A bump stock does not convert a semiautomatic rifle into a machinegun any more than a shooter with a lightning-fast trigger finger does.”

To say that a bump stock merely “helps” the shooter “press the trigger against his finger very quickly thereafter” does not fully capture how it actually works. At oral arguments, the Justice Department noted that the bump stocks at issue in this case allow someone to fire between 400 and 800 rounds per minute, or about six to 12 rounds per second. Even a shooter with a “lightning-fast trigger finger” would struggle with that, especially for a sustained period of time.

In her dissent, Sotomayor wrote that she did not think this case was a particularly difficult one. “Today, the Court puts bump stocks back in civilian hands,” she wrote. “To do so, it casts aside Congress’s definition of ‘machinegun’ and seizes upon one that is inconsistent with the ordinary meaning of the statutory text and unsupported by context or purpose. When I see a bird that walks like a duck, swims like a duck, and quacks like a duck, I call that bird a duck.”

To reach that conclusion, Sotomayor argued that only the first pull of the trigger counted as a “single function of the trigger,” and everything after that was just part of the intended firing sequence.  “All of the textual evidence points to the same interpretation,” she wrote. “A bump-stock-equipped semiautomatic rifle is a machinegun because (1) with a single pull of the trigger, a shooter can (2) fire continuous shots without any human input beyond maintaining forward pressure.”

She also directly criticized each of the six justices in the majority for avoiding the most commonsense reading of the statute. “The majority creates a definition of the statute that bans only ‘traditional’ machineguns, even though its definition renders Congress’s clear intent readily evadable,” she wrote. “Every member of the majority has previously emphasized that the best way to respect congressional intent is to adhere to the ordinary understanding of the terms Congress uses.” Sotomayor then included a lengthy paragraph quoting each of the six justices saying in prior cases that courts must interpret laws based on their ordinary meanings.

In a short concurring opinion, Justice Samuel Alito claimed that there was “simply no other way to read the statutory language.” Perhaps with an eye toward potential criticism of the justices for their ruling, he attributed the problem to Congress for not legislating after the Las Vegas massacre and ATF for trying to ban bump stocks itself. “There is a simple remedy for the disparate treatment of bump stocks and machineguns,” he wrote. “Congress can amend the law—and perhaps would have done so already if ATF had stuck with its earlier interpretation. Now that the situation is clear, Congress can act.”

Alito is correct that there was bipartisan interest in passing new legislation to ban bump stocks in 2017. But it was quickly quashed by gun rights groups and Republican lawmakers. Then–House Speaker Paul Ryan and the National Rifle Association instead called upon ATF to ban bump stocks under existing federal law. The Trump administration followed suit, and the agency announced a new rule, just over a year after the shooting, that reinterpreted the NFA to ban the sale and possession of bump stocks throughout the country.

Hopes for a legislative fix are likely slim to none for the foreseeable future. Congress is barely a functioning institution at the moment, thanks to Republican control of the House. Even if it were, lawmakers are typically most likely to pass legislation when current events compel them to act. It has now been six years since the Las Vegas massacre. Memories have faded, emotions have cooled, interest has shifted elsewhere—for everyone but the survivors and the loved ones of the dead, at least.

And it’s worth noting that only Alito signaled that he might uphold such a law—none of the five other conservative justices joined his concurring opinion. It is not impossible to imagine that Congress passes a legislative ban, the White House signs it, and then this roster of justices strikes it down again on Second Amendment grounds. After all, there probably isn’t a “historical analogue” for banning bump stocks that could meet Bruen’s stringent history-and-tradition test.

Hypertechnical statutory arguments cannot hide the cold reality here: The Supreme Court’s decision means that bump stocks will remain legal until a sufficient number of mass shootings are committed with them to compel the elected branches to restore what the justices have arbitrarily removed. Americans already pressured their elected officials to act once to address this problem, and they did. Whatever this is, it doesn’t feel like American self-government.