What Weapons Get 2nd Amendment Protection?

The Second Amendment protects the right to bear arms, but what weapons exactly are covered by this Constitutional provision? Professor Jake Charles of Pepperdine Law School sheds new light on a long-standing question. Is it merely firearms that the Constitution protects, or does the word "arms" also refer to other weapons? Professor Charles explains existing case law, including Supreme Court precedent, to clarify which weapons, such as stun guns and nunchucks, are protected under the Second Amendment.

While questions remain as to which weapons are included under the Second Amendment, Professor Charles shares the legal tests and benchmarks often employed by courts in evaluating the right to bear arms.  First, the weapon must pass the "common use test." Under this judicial yardstick, courts seek to determine whether a weapon is in common use by law-abiding citizens for lawful purposes. Weapons, even in common use, can still be regulated where they are determined to be “dangerous and unusual.”

The United States Supreme Court provided some guidance on the ability of states to regulate "dangerous and unusual weapons" in the landmark case of District of Columbia v. Heller (2008). In this case, Justice Antonin Scalia, writing for the majority, made it clear that the right to bear arms is not unlimited and does not prohibit laws forbidding the carrying of "dangerous and unusual weapons." Heller specifically notes that the possession of "M-16 rifles and the like" could be banned, describing them as "dangerous and unusual."  Professor Charles delves into the nuances of the 'dangerous and unusual' test and also examines another Supreme Court case, Cayetano v. Massachusetts (2016), which further elucidates the constitutional meaning of 'Arms.

The Caetano case challenged the constitutionality of a Massachusetts law that prohibited the possession of stun guns, thereby raising questions about the definition of “Arms” in the Second Amendment. Jaime Caetano, the petitioner, had been convicted of possessing a stun gun, which she carried for self-defense purposes. The Massachusetts Supreme Judicial Court upheld her conviction, reasoning that stun guns were not the type of weapons that the Second Amendment was intended to protect, in part because they were nonexistent at the time the Second Amendment was enacted. The Supreme Court, however, vacated the Massachusetts court's judgment, expanding the legal meaning of "bearable" arms. Though short and unsigned, Professor Charles explains that the Caetano decision has significant implications for Second Amendment jurisprudence, highlighting that even modern weapons can qualify for constitutional protection.  

Additional Resources

This video was created in collaboration with the Duke Center for Firearms Law, dedicated to the development of firearms law as a scholarly field, through the development and support of reliable, original, and insightful scholarship, research, and programming on firearms law. 

Related Cases and Videos:

  • NYSRPA v. Bruen (2022) – Supreme Court case which expanded Second Amendment rights outside of the home and established a new Second Amendment test. 
  • Caetano v. Massachusetts (per curiam opinion, 2016) – Established that the Second Amendment protections involving bearable arms extend beyond the weapons in existence at the time of the founding. 
  • Text, History and Tradition Test – Established by the 2022 landmark decision, NYSRPA v. Bruen, the text, history, and tradition test now governs laws restricting the right to keep and bear arms – invalidating any gun laws that fail to meet its standard.
  • District of Columbia v. Heller (2008) – landmark Supreme Court decision that held that the Second Amendment to the U.S. Constitution protects an individual's right to keep and bear arms for traditionally lawful purposes such as self-defense within the home.

What Weapons Get 2nd Amendment Protection? Brief Transcript

Interview with Constitutional Scholar Professor Jacob Charles

Host, Joel Cohen: The Second Amendment enshrines the "right to bear Arms." Today we'll be talking about what exactly Arms means under the Second Amendment. Hello and welcome to TalksOnLaw; I'm Joel Cohen. Today, we're joined remotely by Professor Jake Charles, a professor of constitutional law at Pepperdine law school. Professor Charles, let's talk about arms. 

Professor Jacob Charles: All right, let's do it.

Host: When it comes to the right to bear arms, we all think of guns, but what does it actually mean under the Second Amendment?

Professor Charles: Yeah, so the Second Amendment says "Arms," not firearms. You wouldn't notice that from our public and popular discourse about the Second Amendment and even many court cases confuse the notion of arms and equate arms with firearms, but in fact, the Supreme Court in its Heller Decision in 2008 said that the term is quite broad, that it extends to all weapons that constitute bearable arms – kind of circular definition of arms – but the Court said weapons of offense or defense. So, presumptively a large category of weapons fall within the definition of arms.

Professor Eric Rubin at SMU law school has a really good law review article that talks about the gun-centricity of Second Amendment doctrine and how that warps our understanding of what weapons are covered because most of the cases are, as you suggest, about guns themselves and the Supreme Court has not really said much more about what particular weapons are encompassed, within that broad definition but it's given essentially two flip sides of the same coin about what weapons are in and what weapons are out.

The Common Use Test
So, what weapons are in involves what's called the "common use test." This is a test the Supreme Court hinted at, but which has been developed in lower courts. And what that test says is, weapons that are in common use (1) by law-abiding citizens, (2) for lawful purposes get second amendment protection. So, weapons that are not in common use by law-abiding citizens for lawful purposes presumptively don't have constitutional protection.

Host: Interesting, so here are we talking about, I'm imagining bow and arrows that a hunter might use or a pocket knife that that may be common.

Nunchucks under New York Law

Professor Charles: Sure, yeah, there have been cases about certain kind of knives and knife restrictions – restrictions in the lengths of knives and some courts said those are unconstitutional. Same thing with nunchucks. There have been nunchucks cases where courts said some kind of the regulations of those are unconstitutional. 

Host: Wait, there are places where nunchucks are illegal?

The "Dangerous and Unusual" Test Established by Heller

Professor Charles: There was a New York case. I don't know if they were illegal, but they were certainly regulated in certain ways or at least certain type of nunchucks so there was a New York case, absolutely.  Andd so, the flip side though is that weapons that are "dangerous and unusual" do not get protection. So even if you might think, oh well that's fairly common. if it's dangerous and unusual. usually meaning if it's mostly used by those who are intent on doing harm unlawfully, then they're not going to be protected. And the paradigmatic weapon there is a machine gun. So, machine guns, the Supreme Court has said, can be banned. In Heller it said M-16s and the like can be banned and so machine gunsl, even if they were say frequently used by sport shooters, they would still not get constitutional protection because they're dangerous and they're unusual.

Host: Does the dangerous and unusual mean there can be restrictions on guns that are dangerous and guns that are unusual or they must be both dangerous and unusual?

Professor Charles: this is a an interesting debate because there's been an actual discussion over the "and" versus the "or." Some of the historical sources the Supreme Court cited used an "or." So, Blackstone, for example, says dangerous or unusual weapons. The Supreme Court in Heller said "dangerous and unusual weapons," and then the Supreme Court suggested that it's a conjunctive test that it has to be dangerous and unusual. And one of the reasons for that is that guns are recognized as inherently dangerous. There's no objection to recognizing guns as a dangerous weapon, in fact that's part of their appeal. They're dangerous weapons, and so how to interpret that, the Supreme Court hasn't said. In fact, courts are all over the map. Some suggestions are that weapons that are "unusually dangerous" are the kinds of weapons that fall outside the scope of the Second Amendment, but one thing we know for sure. at least we have hints of what the Supreme Court has said. is that weapons that are very commonly used and mostly used by law-abiding citizens for lawful purposes, those kind of weapons are weapons that do get presumptive coverage under the Second Amendment.

Host: As a non-expert, it seems to me that "unusually dangerous" should be what we what we cared more rather than how common or unusual the weapon was.

Professor Charles: I think that's right I think one of the problems is establishing a baseline there because you know weapons that might be unusually dangerous in 1791...  An AR-15 probably would have been considered unusually dangerous in 1791 when there weren't the repeating rifles that we saw later in that century. And so weapons that they might have thought would be unusually dangerous, today, are actually commonplace. So one you know one question for this test is establishing a baseline,

Host: That's another point that it's a moving benchmark. So it may be "unusually dangerous" at a given time but not in another.

Professor Charles: I think that's right

Host: Why don't we take a look at some case law. What have we seen in recent times where courts have been asked to interpret what is an "Arm" under the Second Amendment?

Caetano v. Massachussets and Is a Stun Gun Is Protected?

Professor Charles: Sure so one of the most consequential decisions was a decision by the Massachusetts high court that said stun guns are not protected arms under the Second Amendment and it used kind of a curious test by saying well these weren't common in 1791, therefore they don't get protection today. And the Supreme Court, in what's called a per curiam opinion, this is an unsigned opinion so we don't know the author of it. It's very short, it's a two-page opinion. The Supreme Court said that's the wrong method, you shouldn't use that method. Now it did not say precisely how to assess those kinds of claims, but it said the Massachusetts court did it wrong. It said we made clear in Heller that weapons that were not in existence in 1791, they're still protected because common use would mean common use for law-abiding citizens today and not common use only in 1791. In that decision. called Caetano v. Massachusetts, the Supreme Court clearly said that you can't ban weapons just because they didn't exist in 1791. So the argument that you often hear in the public by those in favor of stricter gun laws is, well, how can anything other than a musket be protected if we're doing originalism? And the Supreme Court at least gave its answer to say, well, in the same way that the First Amendment protects speech technologies that didn't exist at the time the First Amendment was ratified, so also weapons that weren't in existence at the time the Second Amendment was ratified are also protected. 

Host: It seems like the Massachusetts court was was being a little clever. The Supreme Court has suggested that the tradition and the laws that existed at the time of the ratification of the Second Amendment are important to understanding how to regulate guns, so they kind of flipped it, and said, well if the guns didn't exist at that time, then the protection shouldn't apply. 

Professor Charles: Yeah, I think that's right. I think it was being a little bit too clever. Because we see the Caetano decision from the Supreme Court, no noted dissents. So even the justices who dissented in Heller and thought Heller was wrong, they didn't dissent in this decision. So all of the justices, at least we don't have the recorded votes but no justices dissented from that opinion. So seemingly all the justices said, Massachusetts, you're using the wrong test to apply here. You should be looking at whether or not they're common in common use by law-abiding citizens today.

Host: And I guess there's probably an intuitive argument there that, hey if something way more deadly is constitutionally protected, then why not something that's safer?

Professor Charles: That's right. Yeah Justice Alito in his concurrence to that decision, which is much longer than the per curiam two-page opinion says exactly this. That it would be perverse if you were allowed to say that stun guns are "dangerous and unusual" and so can be banned even though they're much less lethal than what Heller said are protected arms, namely  handguns.

Host: So, Professor, What can be banned? What if I want to walk down the street with, you said nunchucks, what if I want to walk down the street with a five-foot samurai sword here in New York City?

So Which Weapons Are Protected Today?

Professor Charles: Yeah, this is sort of the million-dollar question. The Supreme Court has not taken a case squarely about what weapons are protected. That Caetano case was very little reasoning and all it said was the lower court got it wrong. And so we're seeing now lower courts confronting this question mainly in the context of assault weapon bans. The key question with an assault weapon ban that courts are confronting is, "Are these arms within the mean of the Second Amendment?" Ao are they in common use by law-abiding citizens or are they dangerous and unusual such that they can be regulated in the same way that we regulate machine guns?Here, we're not seeing a lot of agreement among the lower courts about whether or not these kind of weapons are protected under the Second Amendment, or at least what the historical tradition looks like of regulating these types of weapons. So, I think the common use test is the one that most courts have coalesced around. Under the common use to get protection for your 'samurai sword,' you might want to have some evidence about how many samurai swords were sold or possessed or how often they're used in criminal activity, but the common use test doesn't answer the question about how widespread it has to be.  Do you have to show that it's common in one state? Is that enough, even if it's not common in others? If you show that it's in common use today, but it wasn't a decade ago or two decades ago, is that enough? And, what really does it mean to be in common use? Does it have to be used in self-defense incidents? Many gun rights or gun regulation proponents would say things like high capacity magazines – people are on average not using 10 shots when they're using a gun in self-defense, so they say they are not "in common use." The response is, well "common use" just means commonly possessed.

Host: So, maybe it might be used in a gun range? Or the samurai swords might be used in a kids karate studio.

Professor Charles: Exactly

Host: Professor Jake Charles thanks for joining us today 

Professor Charles: Thanks, Joel.