Yes, brass knuckles are illegal in Hawaii. Carrying them is a misdemeanor under Hawaii Revised Statutes 134-51, punishable by up to one year in jail and a $2,000 fine. If you possess or use them while committing another crime, the charge becomes a Class C felony carrying up to five years in prison and a $10,000 fine.1Justia. Hawaii Code 134-51 – Deadly Weapons; Prohibitions; Penalty
What the Law Actually Bans
HRS 134-51 makes it illegal for any unauthorized person to carry concealed or be found armed with metal knuckles (the term the statute uses for brass knuckles), along with dirks, daggers, and blackjacks.1Justia. Hawaii Code 134-51 – Deadly Weapons; Prohibitions; Penalty “Carrying” is broad. It covers the weapon on your body, in a bag, or in your vehicle. Officers can arrest you on the spot without a warrant if they find them.
A common mix-up: brass knuckles are not grouped with switchblades and butterfly knives. Section 134-51 explicitly excludes switchblades, butterfly knives, firearms, and electric guns, which are covered by their own separate statutes.2FindLaw. Hawaii Code 134-51 – Carrying Deadly Weapons
The statute doesn’t set out manufacturing or selling brass knuckles as a standalone offense. Criminal exposure comes from carrying, possessing, or being found armed with them. Selling to someone else still carries legal risk, because you’re arguably helping that person commit a crime.
Penalty for Carrying: Up to One Year in Jail
Simple possession or carrying under HRS 134-51(a) is a misdemeanor. The maximum jail term is one year.3Justia. Hawaii Code 706-663 – Sentence of Imprisonment for Misdemeanor and Petty Misdemeanor The court can add a fine of up to $2,000.4Justia. Hawaii Code 706-640 – Authorized Fines After conviction, the weapon is destroyed by the chief of police or sheriff.1Justia. Hawaii Code 134-51 – Deadly Weapons; Prohibitions; Penalty
Don’t treat the misdemeanor label as trivial. The conviction is permanent on your record, and it flags you as having carried a weapon grouped by statute with daggers and blackjacks.
Penalty When Tied to Another Crime: Class C Felony
Under HRS 134-51(b), knowingly possessing or intentionally using a deadly weapon during the commission of any felony or misdemeanor is itself a Class C felony.2FindLaw. Hawaii Code 134-51 – Carrying Deadly Weapons You don’t have to hit anyone with the brass knuckles. Having them on you during another offense is enough.
A Class C felony carries up to five years in prison5Justia. Hawaii Code 706-660 – Sentence of Imprisonment for Class B and C Felonies and a fine of up to $10,000.4Justia. Hawaii Code 706-640 – Authorized Fines The sentence runs in addition to the sentence for the underlying crime, not instead of it, and the court decides whether the two run concurrently or consecutively.2FindLaw. Hawaii Code 134-51 – Carrying Deadly Weapons
There is a second felony route worth knowing. Threatening someone with brass knuckles (a “dangerous instrument”) can support a charge of terroristic threatening in the first degree, also a Class C felony under HRS 707-716.6Justia. Hawaii Code 707-716 – Terroristic Threatening in the First Degree That charge would sit on top of the weapons charge.
The Narrow Exceptions
Hawaii leaves very little room to legally possess brass knuckles.
Authorized by Law
Section 134-51(a) applies only to persons “not authorized by law,” which implicitly exempts law enforcement and other government personnel whose duties require them to carry weapons.1Justia. Hawaii Code 134-51 – Deadly Weapons; Prohibitions; Penalty The general exemption statute, HRS 134-11, covers sections 134-7 through 134-9 and 134-21 through 134-27 — it does not list 134-51.7Justia. Hawaii Code 134-11 – Exemptions So the only carve-out for brass knuckles is the “authorized by law” language inside 134-51 itself.
In Your Own Home
Hawaii law provides a defense if you were lawfully present in your own home at the time of the alleged offense.2FindLaw. Hawaii Code 134-51 – Carrying Deadly Weapons This applies only to the carrying charge under subsection (a). It won’t shield you if you used the weapon during another crime, even inside the home.
Search and Knowledge
Standard criminal defenses still apply. If the police found the brass knuckles through a search that lacked probable cause or a valid warrant, the evidence may be suppressed, and the case usually collapses without the weapon itself. The statute also requires that you “knowingly” carry the item, so if the brass knuckles were in a borrowed bag and you had no idea, that element isn’t met.
Long-Term Consequences Most People Underestimate
Jail and fines are only part of what a conviction costs.
A felony conviction under 134-51(b) permanently bars you from owning, possessing, or controlling any firearm or ammunition in Hawaii, and violating that ban is itself a Class B felony.8Justia. Hawaii Code 134-7 – Ownership, Possession, or Control Prohibited Federal law adds its own parallel restriction, so the prohibition follows you if you leave the state.
Expungement is where people get the worst surprise. Hawaii allows conviction expungement only for a short list of offenses — underage DUI, certain first-time drug offenses, and certain first-time property offenses. Weapons convictions aren’t on that list.9Hawaii Criminal Justice Data Center. Expungements If your case ends in acquittal or dismissal, you can apply to expunge the arrest record under HRS 831-3.2.10Justia. Hawaii Code 831-3.2 – Expungement Orders But a conviction, even the misdemeanor version, stays on your record for life.
Traveling to Hawaii With Brass Knuckles
Hawaii’s ban is among the strictest in the country. Some states permit brass knuckles outright — Texas legalized them in 2019 — and others allow possession with restrictions. None of that matters once you land in Honolulu. Hawaii’s law applies the moment you arrive, whether or not the weapon was legal where you bought it or where you live.