Litigation Highlight: Ninth Circuit Hears Oral Argument in Challenge to Hawaii’s Butterfly Knife Ban
First principles of federalism suggest that state-to-state variety is a feature, not a bug, of the American system. Each state can generally determine for itself how to exercise its police power and provide for public safety. However, recent litigation following the Supreme Court’s Bruen decision suggests that differentiation among state weapons regulations may raise constitutional concerns. Outlier states are now on the defensive when it comes to their sui generis weapons regulations. In Hawaii, a unique approach to knife control faces a Second Amendment challenge.
On February 14, the Ninth Circuit heard oral arguments in Andrew Teter v. Anne E. Lopez. The case involves a challenge to a Hawaii state law banning butterfly knives. The statute, which Hawaii originally passed in 1999, makes it a misdemeanor to knowingly manufacture, sell, transfer, possess, or transport butterfly knives within the state. The state described butterfly knives, also known as balisong knives, in its original briefing as having blades enclosed in a split handle, just as switchblades do. Unlike switchblades, however, the blade in a butterfly knife is produced by manually pulling apart the split handle and turning the knife around rather than by using a spring-action or gravity release mechanism.
The provision banning butterfly knives sits within a larger portion of the Hawaii Revised Statutes that regulates “firearms, ammunition, and dangerous weapons.” The prior sub-sections of the code ban dirks, daggers, blackjacks, slug shots, billy clubs, metal knuckles, pistols, and other deadly or dangerous weapons, along with switchblades.
The parties filed original briefing in the Court of Appeals nearly three years ago, after the District Court for the District of Hawaii granted the state’s motion for summary judgment. However, the Ninth Circuit panel heard arguments only this month, following an extended abeyance and supplemental briefing after the Bruen decision. The panel included Judges Carlos Bea, Daniel Collins, and Kenneth Lee.
In their 31-page supplemental brief filed following Bruen, the plaintiff-appellants argued that the Second Amendment protects the individual right to keep and bear butterfly knives as weapons of self-defense. The brief argued that Hawaii’s outright ban of butterfly knives—residents can neither carry them nor possess them at home—violates that right. Under Bruen’s text, history, and tradition test, appellants said, there are no historical analogues from the Founding that are comparably justified and comparably burdensome to the present-day butterfly knife ban, despite the fact that butterfly knives existed in that period. Appellants further argued that these knives fall squarely within the definition of bearable arms “because they can be held by a person to attack another person in confrontations.”
Appellants asserted that the history books contain no analogues to Hawaii’s butterfly knife ban that might support the state’s decision to ban a weapon that is otherwise presumptively protected under the Second Amendment. During oral argument, appellants pointed out that Hawaii is an outlier in its criminalization of butterfly knives as a matter of both historical and present law. Only one other state — New Mexico — bans butterfly knives outright.
In response, the state’s supplemental brief contended that Hawaii’s butterfly knife ban passes constitutional muster even in a post-Bruen world. The state, which under Bruen bears the burden of producing a relevant historical analogue, appended over 200 pages of evidence from the historical record to its brief. That record, the state suggested, reveals a long historical tradition of knife regulations throughout Hawaiian and U.S. history, dating to the period of the Founding, that supports the present-day ban. Hawaii argued that its ban on butterfly knives and the related switchblade “is part of a tradition of banning weapons that are closely associated with criminals and criminal activity.”
In isolating historical analogues, Hawaii focused on laws from the Founding Era that banned knives (and weapons, generally) associated primarily with criminal activity. The state relied heavily on evidence of Bowie knife regulation. The state argued that the butterfly knife ban is analogous to those laws because it similarly targets weapons used disproportionately by criminals. The state further relied on footnote 9 in the Bruen opinion—which carved out shall-issue handgun licensing—to argue that courts should uphold state regulations when “they do not necessarily prevent law-abiding, responsible citizens from exercising their Second Amendment right[s].”
During oral argument, the panel of judges pushed back on many of the state’s arguments. Notably, Judge Bea pressed the deputy solicitor general of Hawaii on his request for remand to further develop the factual record of historical analogues to Hawaii’s butterfly knife ban. Judge Bea seemed unconvinced that developing the historical record was a factual inquiry worthy of remand. Instead, he suggested that remand would be inappropriate because the state had already enjoyed an adequate opportunity to collect historical statutes and because the history of legislation is question of law, not fact. Notably, the factual record in this case does not include statistics or information regarding the number of butterfly knives in private possession or how frequently they are used in crimes.
Similarly, Judge Bea seemed skeptical of Hawaii’s argument that the relevant category of historical analogues was bans on weapons commonly associated with criminal behavior. The panel expressed doubt that “weapons associated with criminals” constituted a firm enough category to support a legislative ban given the historical record. Instead, Judge Collins and Judge Lee asked for evidence that butterfly knives fell in the category of “dangerous and unusual weapons,” which do not have Second Amendment protection. The Hawaii first deputy solicitor general argued that weapons associated with criminals are generally “dangerous and unusual weapons” that do not benefit from Second Amendment protection.
Notably, counsel for the appellants appeared to suggest that “dangerous and unusual weapons” lack Second Amendment coverage only in “carry” contexts (as opposed to ownership)—this argument wasn’t made explicitly, but counsel stated he would like to preserve it. Appellants’ counsel made this point in response to a question from Judge Lee about whether the “dangerous and unusual weapons” rule should be a freestanding threshold inquiry or, instead, part of the Bruen historical analysis. If courts were to read the “dangerous and unusual weapons” carveout as applying only to laws regulating carriage of such arms, laws banning possession of weapons such as grenade launchers might violate the Second Amendment.
Judge Collins further suggested that, despite Hawaii’s argument to the contrary, Bruen’s endorsement of laws (like shall-issue licensing) that do not restrict law-abiding citizens from exercising Second Amendment rights do not control in analyzing the butterfly-knife law because it is a total ban and not a regulation on carry or use. Bruen footnote 9, Judge Collins implied, should only come into play when a law seeks to regulate the use of weapons by non-law-abiding citizens. The state argued that the narrowness of the law — its application only to butterfly knives — makes footnote 9 analytically relevant.
The Ninth Circuit panel also questioned the Hawaii legislature’s motive for banning butterfly knives (moving beyond Bruen’s history-centric test). The judges expressed some doubt about the state’s argument that the legislative history demonstrated that butterfly knives are disproportionately used by criminals.
Several features of this case stand out, even as the parties await an official ruling from the Ninth Circuit. First, counsel for the appellants argued for an extremely strict historical approach in cases involving weapons that existed at the Founding. Appellants’ counsel claimed that Bruen requires a finding of unconstitutionality whenever a state regulates a weapon that existed at the Founding in a manner that goes beyond the regulations on the books close in time to 1791. This would mean the existence of analogous regulations can only be used to support the constitutionality of legislation regulating arms that did not exist at the Founding. For arms that did exist at the Founding, the government would have to point to legislation that is identical—not merely analogous. If circuit courts are amenable to the application of this sort of strict historical rule, many other non-firearm weapons regulations may be in constitutional danger.
Second, the Ninth Circuit panel is still working out how Bruen alters, or clarifies, preexisting Supreme Court precedent. Judge Lee asked appellants’ counsel whether the “dangerous and unusual weapons” rule from Heller was part of Bruen’s historical-analogue analysis. Appellants’ counsel responded that the rule should be subsumed into the historical-analogue analysis. That approach may result in a significantly narrower “dangerous and unusual weapons” exception to Second Amendment rights than had existed pre-Bruen. Similarly, courts may focus on Justice Alito’s emphasis, in his concurrence in Caetano, that a weapon must be both dangerous and unusual in order for regulation of that weapon to fall outside of the Amendment’s scope.
Third, many questions remain about what a trial court needs to do when considering Second Amendment challenges. What are the “facts” that are relevant to the Bruen inquiry? Do records of historical laws that serve (or fail to serve) as relevant analogues constitute facts that belong in the realm of trial courts, as the state of Hawaii believes, or can they be “found” in the first instance by an appellate court? Are statistics about the prevalence of particular weapons at the Founding, or about current uses of particular weapons, necessary to decide Second Amendment cases? These questions must be answered if the lower courts are to handle Second Amendment cases effectively without the constant specter of a possible remand.
Finally, this case illustrates what much post-Bruen litigation has shown: determining a relevant historical analogue can be tricky. The panel of judges spent little to no time during oral argument asking counsel on either side about the plethora of historical statutes produced by the state that regulated the use of knives. America’s long history of Bowie knife bans, it seems, is not necessarily a substantial enough historical analogue in a Second Amendment case challenging a butterfly knife ban—although the questioning suggested the judges might agree that this tradition would support a ban on the public carry of butterfly knives (rather than a broader ban on possession like Hawaii’s law).
 The case caption was originally Andrew Teter v. Holly T. Shikada, but has since been updated to reflect to the fact that Anne Lopez is now the attorney general of Hawaii.