Ninth Circuit Panel: Knives Are ‘Arms’ Protected by Second Amendment

butterfly knife
Mathieu Wallerand via pexels

A three-judge panel from the United States Court of Appeals for the Ninth Circuit reversed a district court decision upholding Hawaii’s ban on butterfly knives on Monday, noting that “bladed weapons facially constitute ‘arms’ within the meaning of the Second Amendment.”

The three judges on the panel were George W. Bush appointee Carlos T. Bea and  Donald Trump appointees Daniel P. Collins and Kenneth K. Lee.

The case, Teter v. Lopez, was brought by two law-abiding citizens–Andred Teter and James Grell–who wanted to carry butterfly knives for self-defense.

Judge Alan C. Kay, of the United States District Court for the District of Hawaii, ruled in favor of the prohibition against butterflies and the case was appealed to the Ninth Circuit.

Judge Bea wrote the majority opinion for the Ninth Circuit panel, noting, “Like firearms, bladed weapons fit the general definition of ‘arms’ as ‘[w]eapons of offence’ that may be ‘use[d] in wrath to cast at or strike another.’ Id. (cleaned up). Moreover, contemporaneous sources confirm that, at the time of the adoption of the Second Amendment, the term ‘arms’ was understood as generally extending to bladed weapons.”

He added, “Because the plain text of the Second Amendment includes bladed weapons and, by necessity, butterfly knives, the Constitution ‘presumptively guarantees’ keeping and bearing such instruments ‘for self defense.’”

Bea observed that Hawaii attempted to define butterfly knives as “dangerous and unusual weapons,” in hopes of finding wiggle room for a ban against the knives via Heller (2008). But Bea rejected the claim, explaining, “To determine whether a weapon is dangerous and unusual, ‘we consider whether the weapon has uniquely dangerous propensities and whether the weapon is commonly possessed by law-abiding citizens for lawful purposes.’…The record does not support a conclusion that the butterfly knife has uniquely dangerous propensities. The butterfly knife is simply a pocketknife with an extra rotating handle.”

The Ninth Circuit panel reversed and remanded the case to the district court.

The case is Teter v. Lopez, No. 20-15948, in the United States Court of Appeals for the Ninth Circuit.

AWR Hawkins is an award-winning Second Amendment columnist for Breitbart News and the writer/curator of Down Range with AWR Hawkins, a weekly newsletter focused on all things Second Amendment, also for Breitbart News. He is the political analyst for Armed American Radio and a Turning Point USA Ambassador. He was a Visiting Fellow at the Russell Kirk Center for Cultural Renewal in 2010, a speaker at the 2023 Western Conservative Summit, and he holds a Ph.D. in Military History, with a focus on the Vietnam War (brown water navy), U.S. Navy since Inception, the Civil War, and Early Modern Europe. Follow him on Instagram: @awr_hawkins. You can sign up to get Down Range at Reach him directly at


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