() “Ghost guns” could potentially become a thorn in the side of authorities again, despite a Supreme Court ruling from the Biden era, according to a report.

The ruling required background checks and serial numbers for certain kits, requiring them to be treated like complete firearms. The rule was challenged in the Bondi v. VanDerStok federal case, but in March, the Supreme Court allowed it to stand.

“The people who make them, oftentimes, and put them on the street are putting them in the hands of people who are prohibited, putting them in the hands of convicted felons” prohibited from owning completed firearms, said Bill Brooks, chair of the Firearms Committee for the International Association of Chiefs of Police. That’s evidenced, he added, “by the fact that so many of them now are showing up at crime scenes.”

Even with the ruling, gun rights groups now see an opening. They are questioning administrative law, and have left open potential roadblocks, depending on kit designs.

The Trump administration has already ordered the Bureau of Alcohol, Tobacco, Firearms and Explosives to review all Biden-era gun regulations. In February, Trump signed an executive order calling for the review of regulations — including the ghost gun rule.

“We’ve urged the administration to act as quickly as possible,” said Alan Gottlieb, executive vice president of the Second Amendment Foundation. “However, there’s a lot on their plate, and I don’t know how quickly it will happen. But we’d like it as soon as possible.”

Gun control advocates say the order from Trump is an extreme plan, part of an effort to disable firearms regulations entirely.