Federal judges have struck down gun restrictions in the months since a Supreme Court decision that expanded Second Amendment rights, and experts say there is likely more to come.

A judge in West Virginia this month cited the Supreme Court case when he struck down a federal law that required guns to have serial numbers. So did a judge in Texas who ruled last month that people under criminal indictments can still possess guns and a judge who this month tossed New York’s prohibitions on carrying concealed firearms in Times Square, summer camps, subways and theaters.

More than a dozen other challenges to gun control laws are pending in federal courts, which legal experts say could leave holes in efforts to curb gun violence and the use of weapons in crimes.

And with long-standing partisan divisions in Congress over gun control bills, the Supreme Court likely will have final say over the fate of national gun regulations.

Judges now are grappling with how to apply the Supreme Court’s decision from June, which has “led to some pretty bizarre results,” according to Andrew Willinger, executive director of the Center for Firearms Law at Duke University.

In that decision in New York State Rifle & Pistol Association Inc. v. Bruen, the justices struck down New York’s law about who can carry a concealed weapon. In doing so, they for the first time expanded the right to possess a gun outside of the home and laid out a legal test of sorts for gun regulations that looks to the history and tradition of the Second Amendment.

That broad test gave courts, and legislators, little to work with. “What we’ve seen so far is a lot of confusion and uncertainty in how to apply Bruen’s historical test,” Willinger said.

Jacob Charles, an associate law professor at Pepperdine University, said the vague nature of the Bruen decision left trial court judges with the broad ability to interpret history how they saw fit.

Judges interpret

Last week, a judge ruled a federal law that prohibits possession of a firearm with a filed-off serial number was unconstitutional—even though the law is useful and “desirable for our society.”

Judge Joseph Goodwin of the U.S. District Court for the Southern District of West Virginia noted in his decision about the serial number law, referred to as Section 922(k), that the Supreme Court didn’t allow him to take into consideration other factors, such as the ability for law enforcement to solve crimes.

“Certainly, the usefulness of serial numbers in solving gun crimes makes Section 922(k) desirable for our society. But the Supreme Court no longer permits such an analysis,” Goodwin wrote. “Under Bruen, I am limited to considering whether Section 922(k) is ‘consistent with the Nation’s historical tradition of firearm regulation.’”

In New York, a judge interpreted the Bruen case in a way that expanded firearm rights in places such as Times Square and New York City subways even though the Supreme Court’s conservative majority explicitly didn’t rule about gun rights in those locations.

Judge Glenn T. Suddaby of the U.S. District Court for the Northern District of New York tossed out much of New York’s latest concealed carry law, finding there was not enough of a historical precedent to allow prohibitions on carrying firearms in Times Square, summer camps, subways and theaters.

Suddaby wrote that historical precedent instead went against gun bans on public transportation. “Indeed, historical analogues exist containing specific exceptions permitting the carrying firearms while travelling (presumably because of danger often inherent during travel),” Suddaby wrote.

In another case, Judge David Counts of the U.S. District Court for the Western District of Texas found unconstitutional a ban on people under felony indictment having a gun. There, Counts wrote that he doesn’t know “the constitutionality of firearm regulations in a post-Bruen world.”

“This Court does not know the answers; it must only try to faithfully follow Bruen’s framework,” Counts wrote.

Still, a federal judge in California has relied on the Supreme Court decision to uphold a San Jose law that requires liability insurance for gun owners.

The Supreme Court has not weighed in substantively on any of these cases, which are moving through the lower courts. Last week, the U.S. Court of Appeals for the Second Circuit stayed the lower court decision on the New York law.

Gun rights advocates have filed other lawsuits to challenge gun laws, such as a ban on guns on the Metro in Washington, a ban on homemade guns in San Diego or a ban on assault weapons in Colorado.

Charles said the ripple of lower court decisions “may not legally, but practically force the Supreme Court’s hand” to weigh in again. Sweeping decisions could turn federal firearms law into Swiss cheese, with some judges upholding regulations while others strike them down.

“I don’t think the court would want that kind of disuniformity lasting for too long,” Charles said.

Lawmakers sidelined

While those challenges play out, Congress and state lawmakers have little guidance on what will pass constitutional muster.

Michael Lawlor, a law professor at the University of New Haven, said the Bruen decision and subsequent lawsuits will make it difficult for lawmakers to draft legislation that survives a Supreme Court review.

“I’m urging caution, not hubris. Even if you can pass something that is very comprehensive, maybe you should think twice about it,” Lawlor said.

The Supreme Court’s decision could allow for some gun control approaches to pass muster, but Lawlor said even those will still likely face challenges.

“I think gun control advocates have to think twice about when they’re enacting laws, they have to have in the back of their mind that this may get to the Supreme Court and they want to have it as unassailable as possible,” Lawlor said.

While some states have passed new laws to respond to the Bruen decision, such as pending legislation in New Jersey to ban guns in places like schools and government buildings and to shore up concealed carry licensing requirements, the prospect of a federal effort to address Bruen’s consequences is less likely.

Recent efforts to change federal gun laws have withered in Congress. The major gun violence package that passed earlier this year changed one provision of federal firearms law, an expansion of background checks for 18- to 21-year-old gun buyers to include juvenile records.

Other proposals have stalled in the evenly divided Senate, including an expansion of background checks more broadly and an expansion of gun rights forfeiture for people convicted of misdemeanor domestic violence against a dating partner.

Susan Liebell, a political science professor at Saint Joseph’s University in Philadelphia, said that gun control provisions with large amounts of popular support are unlikely to advance in the current political environment.

“The way this should play out politically is that senators and representatives would be punished in elections because they don’t support the kind of gun safety laws that Americans want,” Liebell said. “However, there’s no evidence that Americans are willing to vote on gun safety the way they’re willing to vote on the economy.”

Liebell also pointed out that the conservative legal movement spent much of the last four decades building the Supreme Court majority that led to the Bruen decision, one that is not likely to go away anytime soon.

“We’re not really talking about history, we’re not really talking about the original interpretation of the Second Amendment, we’re talking about the number of votes that you have on the Supreme Court,” Liebell said.