Brass knuckles are legal to own, buy, sell, and carry in Missouri. A 2022 law repealed the old ban on possessing and selling them, so keeping a pair at home or on your person is no longer a crime under state law. The catch: Missouri still classifies metal knuckles as a “deadly weapon,” which means where you take them and how you use them can still land you in serious trouble.
What the 2022 Law Changed
Before August 28, 2022, brass knuckles sat on Missouri’s list of prohibited weapons under RSMo 571.020, and possessing, making, transporting, or selling them was a criminal offense.1Missouri Revisor of Statutes. Missouri Revised Statutes RSMo Section 571.020 HB 1462, passed that year, repealed the prohibition on possessing and selling brass knuckles along with firearm silencers and switchblade knives.2Missouri Senate. House Bill Summary – HB 1462
Since that date, owning a pair, keeping them at home, or carrying them on you is not a crime under state law. The commercial side opened up at the same time: manufacturing, buying, selling, transporting, and repairing brass knuckles are all permitted. The legislation did not create any age restriction specific to brass knuckles, licensing requirement, or registration obligation.
Why the “Deadly Weapon” Label Still Matters
Legalization did not change how the criminal code defines the item. Missouri’s RSMo 556.061 still lists “metal knuckles” as a “deadly weapon,” right alongside firearms, switchblade knives, daggers, blackjacks, and billies.3Missouri Revisor of Statutes. Missouri Revised Statutes RSMo Section 556.061 That label does not make possession illegal. It does raise the ceiling on what you can be charged with if you use them against someone, and it feeds into several other weapons statutes.
One narrow point about the statutory wording: the definition says “metal knuckles.” Plastic, polymer, or carbon fiber versions are not named in the deadly weapon definition, though a prosecutor could still argue they fit the broader “dangerous instrument” category depending on how they were used.3Missouri Revisor of Statutes. Missouri Revised Statutes RSMo Section 556.061
Where You Cannot Carry Them
The same 2022 package created RSMo 571.024, which bars brass knuckles from the locations where firearms are already restricted under RSMo 571.107. The restricted places include:
- Police, sheriff, and highway patrol offices without the chief officer’s consent
- Polling places on election day (within 25 feet)
- Jails, prisons, and juvenile correction centers
- Buildings or rooms occupied by circuit, appellate, or supreme courts
RSMo 571.107 lists additional restricted areas worth reviewing if you plan to carry regularly.4Missouri Revisor of Statutes. Missouri Revised Statutes RSMo Section 571.107
Carrying brass knuckles into one of these places is not a criminal offense. It triggers civil penalties instead: up to $100 for a first violation, up to $200 for a second within six months, and up to $500 for a third or subsequent violation within a year. Refusing to leave when asked can also bring a citation. The scheme is lighter than the criminal exposure for carrying a firearm into the same locations.
When Carrying Becomes a Crime
Missouri draws its hardest line at how you use the weapon. RSMo 571.030 makes it a crime to exhibit “any weapon readily capable of lethal use” in an angry or threatening manner, and because metal knuckles are classified as deadly weapons, they clear that threshold.5Missouri Revisor of Statutes. Missouri Revised Statutes 571.030 – Unlawful Use of Weapons Flashing them during an argument, using them to intimidate, or swinging them in an assault all fall within this statute.
Penalties under 571.030 vary with the conduct and the person’s record. A threatening exhibition is generally a misdemeanor, but prior convictions, injury to another person, or use during certain felonies can push the charge to the felony level with substantial prison time.5Missouri Revisor of Statutes. Missouri Revised Statutes 571.030 – Unlawful Use of Weapons Using brass knuckles while committing a felony can also trigger a separate armed criminal action charge under RSMo 571.015, which carries its own mandatory minimum sentence on top of the underlying crime.
Self-Defense: A Real Catch
Missouri lets you use physical force in self-defense when you reasonably believe it is necessary to protect yourself or someone else, under RSMo 563.031.6Missouri Revisor of Statutes. Missouri Revised Statutes 563.031 – Use of Force in Defense of Persons Missouri is a stand-your-ground state, so you have no duty to retreat in any place you have a right to be. The force you use must still be proportional. Deadly force is only justified if you reasonably believe it is necessary to prevent death, serious physical injury, or a forcible felony.
That proportionality rule is the practical problem for anyone carrying brass knuckles for defense. Because metal knuckles are legally classified as a deadly weapon, using them could be treated as deadly force, even if you did not intend to kill anyone. A prosecutor can argue that reaching for a classified deadly weapon during an ordinary fistfight was more force than the situation called for. Legal to carry does not mean legally safe to use in every scuffle.
Buying, Selling, and Shipping
Retailers can stock brass knuckles and sell them in stores or online without running into the old 571.020 ban. No state licensing or registration applies. Shipping within Missouri is not restricted by state law. Shipping across state lines is a different matter: several states still ban brass knuckles outright, and the destination state’s law controls, so sending a pair into one of those states can create legal problems for the sender, the recipient, or both.
Flying and Traveling Out of State
Federal weapons law, including 18 U.S.C. ยง 922, focuses on firearms and ammunition rather than handheld impact weapons, so there is no specific federal rule against transporting brass knuckles across state lines. Any trip through a state where they are illegal exposes you to that state’s law. Missouri’s legalization stops at the border.
If you fly, the TSA does not allow brass knuckles in carry-on bags. You can pack them in checked luggage, but the TSA warns that if a checked bag is opened and contains an item that is illegal at the destination, agents are required to report it to local law enforcement.7Transportation Security Administration. Brass Knuckles Check the destination state’s law before you pack.
City and County Rules
Missouri’s state preemption law, RSMo 21.750, blocks cities and counties from passing their own regulations on firearms, ammunition, and related components.8Missouri Revisor of Statutes. Missouri Revised Statutes RSMo Section 21.750 That preemption language is specific to firearms and ammunition and does not explicitly mention brass knuckles. Whether a city could ban them locally is an open question. No widely publicized local bans appear to be in place, but if you live in or visit a Missouri city with strict municipal weapon rules, the local code is worth a look.