Historical Tradition Standard Permits Massachusetts Ban on Assault Weapons and Large-Capacity Magazines

Introduction

Capen v. Campbell, 1st Cir. No. 24-1061 (Apr. 17, 2025), is a challenge by a private citizen and a gun-rights organization to a Massachusetts statute prohibiting the sale, transfer or possession of “assault weapons” and “large capacity feeding devices” (LCMs). Plaintiffs contended that the prohibition violated the Second Amendment. After the District Court denied plaintiffs a preliminary injunction, the First Circuit affirmed, applying the U.S. Supreme Court’s decision in New York State Rifle & Pistol Ass’n v. Bruen and later decisions refining Bruen’s historical-tradition test. This commentary examines the factual and procedural context, distills the court’s holdings and reasoning, and explores the decision’s implications for future Second Amendment litigation.

Summary of the Judgment

In a published opinion authored by Judge Katzmann, the First Circuit rejected plaintiffs’ argument that Massachusetts’s blanket ban on certain semiautomatic rifles (including the AR-15), semiautomatic handguns with specified military-style features, and magazines holding more than ten rounds could not survive Second Amendment scrutiny. Applying the two-part Bruen test, the court assumed without deciding that the banned weapons and magazines fell within the Amendment’s text but concluded that the statute is consistent with the Nation’s historical tradition of prohibiting “dangerous and unusual” arms. The court further held that an assault-weapon ban and an LCM ban are each supported by long-standing analogues—ranging from colonial gunpowder restrictions to nineteenth-century bans on Bowie knives and twentieth-century machine-gun and short-barreled shotgun regulations. Because plaintiffs could not demonstrate a likelihood of success on the merits, the court affirmed the District Court’s denial of a preliminary injunction.

Analysis

1. Precedents Cited

District of Columbia v. Heller, 554 U.S. 570 (2008)
Held that the Second Amendment protects an individual right to possess handguns in the home and recognized longstanding prohibitions on “dangerous and unusual weapons.”
New York State Rifle & Pistol Ass’n v. Bruen, 597 U.S. 1 (2022)
Established a two-part test: (1) whether the challenged regulation is covered by the Amendment’s text, and (2) whether it is consistent with the Nation’s historical tradition of firearm regulation.
United States v. Rahimi, 602 U.S. 680 (2024)
Clarified that historical analogues need not be “dead ringers” or “historical twins,” but must address comparable societal concerns and impose comparable burdens.
Ocean State Tactical, LLC v. Rhode Island, 95 F.4th 38 (1st Cir. 2024)
Applied Bruen to uphold a statewide ban on magazines holding more than ten rounds, finding sufficient historical analogues in powder-container statutes and early magazine restrictions.
Winter v. Nat. Res. Def. Council, Inc., 555 U.S. 7 (2008)
Described the extraordinary nature of preliminary injunctions and articulated the four-factor test, including the indispensable element of likelihood of success on the merits.

2. Legal Reasoning

The First Circuit began by restating the Bruen framework: if a regulation burdens conduct covered by the Second Amendment’s text, the government must show it comports with historical tradition. For preliminary relief, plaintiffs must show a likelihood of success under that test. The court adopted a “nuanced approach” to historical analogy, assessing first how the ban burdens self-defense and then why the legislature enacted it, before comparing those burdens and justifications to historical analogues.

Burden on Self-Defense (“How”)
Plaintiffs offered no record evidence of AR-15s or other banned weapons used in civilian home defense. Expert affidavits demonstrated that semiautomatic “assault weapons” like the AR-15 are less practical for most self-defense scenarios than handguns and inherently more destructive. The court viewed this as a relatively light burden—no greater than historical restrictions (e.g., Bowie-knife and trap-gun bans) tolerated by our tradition.

Legislative Justification (“Why”)
Massachusetts enacted its assault-weapon and magazine ban in response to mass-shooting events and rising gun violence. The court held that this legislative purpose closely parallels historical statutes enacted to respond to particular public-safety threats—whether colonial gunpowder limits aimed at preventing accidental explosions, eighteenth- and nineteenth-century bans on spring-loaded trap guns, or nineteenth-century prohibitions on large-bladed Bowie knives popular among violent criminals.

Comparative Analysis
Because both the burdens and justifications are “relevantly similar” to those in the historical tradition, the court deemed the modern prohibitions constitutionally permissible. To defeat a facial challenge, the government need only show that the statute is valid in some applications. The AR-15 and LCM prohibitions each satisfied that requirement, so plaintiffs could not meet their burden of demonstrating a likelihood of success on the merits.

3. Impact

Capen v. Campbell reaffirms and extends first-circuit precedent upholding firearm regulations under Bruen’s historical-tradition test. It underscores the court’s willingness to draw broad analogies between modern bans on semiautomatic weapons and long-standing prohibitions on discrete classes of dangerous arms. The decision is likely to guide lower courts evaluating assault-weapon and large-capacity-magazine restrictions, signaling that legislatures may address mass-shooting threats through category-wide bans when backed by historical counterparts. It also showcases the narrower universe for facial Second Amendment challenges once a legislature demonstrates at least one valid application.

Complex Concepts Simplified

Bruen’s Two-Part Test – First ask whether the firearm or accessory falls under the Amendment’s textual protection (e.g., “arms” kept for defense). If so, then ask whether historical regulations at the founding or shortly thereafter justify analogous modern prohibitions.
“Dangerous and Unusual” Weapons – Heller recognized that arms perceived as both especially lethal and not commonly used for lawful purposes can be excluded from constitutional protection.
Historical Analogue – A modern law need not replicate a specific 1790s statute; it must address a similar societal problem and impose a similar or lesser burden on the right to keep and bear arms.
Facial Challenge vs. As-Applied – A facial challenge asserts that no application of a statute can be constitutional. Defeating facial relief requires the government to identify at least one lawful application.

Conclusion

Capen v. Campbell solidifies the First Circuit’s embrace of Bruen’s historical-tradition approach. By analogizing Massachusetts’s assault-weapon and large-capacity-magazine ban to centuries-old prohibitions on particularly dangerous armaments, the court held that the modern restrictions survive Second Amendment scrutiny. Plaintiffs failed to demonstrate a likelihood of success on the merits, so the denial of preliminary relief was affirmed. This decision will be cited by courts evaluating broad statutory firearm bans, reinforcing that well-supported historical analogues can sustain categories of regulation aimed at addressing contemporary public-safety challenges.