Amicus Brief Filed in Hawaii Butterfly Knife Second Amendment Case

While the COVID-19 pandemic has interrupted almost all legislative efforts this year, Knife Rights continues its efforts to serve our knife community and Rewrite Knife Law in America™.

Knife Rights Foundation today announced the filing of an important Amicus Curiae (Friend of the Court) brief in a Second Amendment lawsuit currently before the United States Court of Appeals for the Ninth Circuit. The case, captioned Teter v. Connors, challenges the State of Hawaii’s outright ban on butterfly knives. You can view or download the brief at

Previously, the district court ruled in favor of the State on its motion for summary judgment, finding that Hawaii’s butterfly knife ban “does not severely burden” the Second Amendment and that it survives intermediate scrutiny because it “further[ed] the State’s important interest to promote public safety by reducing access to butterfly knives, which leads to gang related crime.” If that sounds like a regurgitation of the baseless arguments used to enact switchblade bans in the 1950’s, that’s because it is.

Balisong knives are legal to possesses and carry in at least 43 states (16 because of Knife Rights’ efforts repealing switchblade and butterfly knife bans since 2010), and Hawaii is one of only three states that specifically ban these knives. The district court’s flawed analysis failed to consider that Hawaii had no ban on these commonly available knives until 1999, and data does not show that the ban was tailored to an actual problem, let alone that it meaningfully reduces crime.

The Knife Rights coalition brief clearly shows that under the U.S. Supreme Court’s precedents, including the District of Columbia v. Heller decision, the knives are not both “dangerous and unusual,” are commonly possessed for lawful purposes, and are protected under the Second Amendment. That’s why, Knife Rights and the other amici argue, the State’s prohibition must fail.

“Butterfly knives, like all knives, are arms protected by the Second Amendment. It is time states like Hawaii stop banning knives in common use based on a fictional threat derived from 1980’s action movies,” explained the brief’s author, attorney John W. Dillon of Dillon Law Group APC.

“Hawaii’s ban on butterfly knives is both irrational, as are all such knife bans, and unconstitutional under the Second Amendment,” said Knife Rights’ Chairman, Doug Ritter. “Knife Rights is proud to be able to support this appeal of an absurd ruling by the district court and appreciate the collaboration and support from our good friends at San Diego County Gun Owners and Firearms Policy Coalition.”

“The ability to defend yourself is important to our members and we are proud to fight for Second Amendment rights in all forms,” commented Michael Schwartz, San Diego County Gun Owners PAC’s executive director.

“FPC is delighted to join our friends at SDCGO and Knife Rights in filing this brief to defend Second Amendment rights,” said FPC Director of Research, Joseph Greenlee. “Butterfly knives are important self-defense tools and certainly among the arms that the people have a right to keep and bear.”

Click here to read the Amicus Curie brief.

Click here to read the 2013 law review article, “Knives and the Second Amendment,” authored by noted Second Amendment scholars Dave Kopel, Clayton Cramer and Joe Olson. This article provides the scholarly foundation for many of the positions in the original case and this brief.

About Knife Rights Foundation

The 501(c)(3) Knife Rights Foundation ( is dedicated to defense of knife owners’ civil rights. The Foundation also works to educate knife owners, public officials and the general public about knife and edged tool related laws and regulations.

About San Diego County Gun Owners Political Action Committee

Founded in 2015, the San Diego County Gun Owners ( a registered political action committee (FPPC ID #1379388) and advocacy organization focused on organizing the gun industry and community and protecting the U.S. Constitution’s Second Amendment right to bear arms.

About Firearms Policy Coalition

Firearms Policy Coalition ( is a 501(c)4 grassroots nonprofit organization. FPC’s mission is to protect and defend constitutional rights—especially the right to keep and bear arms—advance individual liberty, and restore freedom through FPC Law, FPC Research, FPC Policy, FPC Grassroots, and other programs.