MA GUN LAWYER

The latest chapter in United States v. Peterson may prove to be one of the most consequential Second Amendment cases since Bruen. What began as a challenge to the federal regulation of firearm suppressors has now evolved into a case that places the Supreme Court squarely in the middle of a fundamental constitutional question: Are suppressors protected by the Second Amendment, and if so, how far can the federal government go in regulating them?

What Happened in Peterson?

The Fifth Circuit initially issued a February 2025 opinion holding that suppressors are not “Arms” protected by the Second Amendment because they are merely accessories rather than weapons themselves. The panel reasoned that a suppressor cannot independently be used for self-defense and therefore falls outside the constitutional text.

That ruling immediately generated intense criticism from Second Amendment advocates because it appeared difficult to reconcile with the Supreme Court’s decisions in District of Columbia v. Heller and New York State Rifle & Pistol Association v. Bruen, both of which emphasize text, history, and tradition rather than judicial balancing tests. Critics argued that many items commonly possessed and necessary for the effective operation of firearms—including magazines, sights, and other components—might be vulnerable under the panel’s reasoning.

The Fifth Circuit then took the unusual step of withdrawing that opinion. When the court later reissued its decision, it changed course. Rather than holding suppressors categorically outside the Second Amendment, the court assumed for purposes of argument that suppressors are protected arms and instead upheld the National Firearms Act’s registration regime as a constitutional “shall-issue” licensing system.

That shift did not resolve the controversy—it arguably made Supreme Court review more likely.

Why This Case Creates a Supreme Court Problem

The Supreme Court generally grants certiorari when lower courts are divided, when an important federal question is presented, or when a lower court appears to have created a new constitutional framework.

Peterson potentially checks all three boxes.

The Fifth Circuit’s revised opinion effectively held that the NFA suppressor-registration system resembles the “shall-issue” licensing systems that the Supreme Court favorably discussed in Bruen. The court concluded that the registration requirement could survive even assuming suppressors are constitutionally protected.

That creates a significant unresolved question:

Can the federal government require registration and prior approval before a citizen may possess a constitutionally protected arm?

The Supreme Court has never directly answered that question.

Bruen addressed carry permits. Heller addressed handgun bans. Rahimi addressed disarmament of individuals subject to domestic violence restraining orders. None addressed the National Firearms Act’s registration-and-approval structure.

The Growing Tension with Bruen

From a pro-Second Amendment perspective, the Fifth Circuit’s approach appears difficult to reconcile with Bruen‘s rejection of interest balancing.

The government has long argued that suppressors are heavily regulated because of public-safety concerns. Yet Bruen specifically instructed courts not to uphold firearm regulations simply because judges believe them useful or desirable. Instead, the government must identify a historical tradition supporting the regulation. The Fifth Circuit avoided much of that inquiry by analogizing the NFA system to modern licensing schemes.

For gun-rights advocates, that is precisely why Supreme Court review is necessary.

If the NFA registration process can be justified merely because it resembles a licensing system, then the same rationale could potentially be applied to numerous other categories of protected arms.

Why the Supreme Court May Have Little Choice

One reason the Court may feel compelled to take Peterson is that the case presents a clean vehicle.

The petitioner entered a conditional guilty plea and preserved the constitutional issue. The case directly involves federal law rather than complicated state-law questions. And the question presented goes to the heart of how Bruen is to be applied. Moreover, Peterson has already reached the Supreme Court. A petition for certiorari was docketed in March 2026.

The Justices have spent the last several years repeatedly correcting lower courts that, in their view, have failed to faithfully apply Bruen. If the Court believes the Fifth Circuit has effectively created a new category of firearm regulation exempt from rigorous historical scrutiny, it may feel obligated to intervene.

The Broader Implications

The significance of Peterson extends far beyond suppressors.

If the Supreme Court ultimately holds that suppressors are protected arms, that ruling could have implications for challenges involving magazines, firearm components, and other accessories commonly possessed by law-abiding Americans.

Conversely, if the Court accepts the Fifth Circuit’s licensing rationale, governments around the country will likely argue that many forms of prior approval, registration, and permitting requirements are constitutionally permissible so long as they are administered on a “shall-issue” basis. That debate reaches far beyond federal suppressor law. It touches the future of firearm licensing generally.

For states like Massachusetts, where litigation continues over discretionary licensing schemes, “unsuitability” determinations, and other firearm restrictions, Peterson could become a foundational precedent. A Supreme Court decision clarifying the constitutional status of licensing and registration requirements would inevitably influence those battles as well.

Conclusion

Peterson has evolved from a suppressor case into a major test of post-Bruen Second Amendment doctrine. The Fifth Circuit’s unusual procedural history—from declaring suppressors outside the Second Amendment, to withdrawing that opinion, to assuming they are protected while nevertheless upholding federal regulation—highlights just how unsettled the law remains.

With a cert petition now pending before the Supreme Court, the Justices may soon face a question they can no longer avoid: if suppressors are protected arms, can the government require Americans to obtain federal approval and register them before exercising that constitutional right? What about states like Massachusetts, including their far more encompassing registration requirements?

The answer could shape Second Amendment jurisprudence for decades to come.