Are Brass Knuckles Legal in Missouri? (2026 RSMo 571.020)

Brass knuckles are illegal to possess, make, transport, repair or sell in Missouri. RSMo 571.020.1(5) makes it an offense to knowingly do any of those things with "knuckles," and section 571.020.3 classes the offense as a class A misdemeanor. Missouri defines knuckles by their design rather than their material, so the ban is not limited to metal sets. For how other states treat the same item, see our guide to brass knuckles laws by state.

Information last verified on 2026-10-08. This article has not been reviewed by a licensed lawyer.

Jurisdiction scope: This article covers Missouri state law in the Revised Statutes of Missouri: the weapons definitions in 571.010, the prohibited-weapons offense in 571.020, unlawful use of weapons in 571.030, the felon firearm offense in 571.070, armed criminal action in 571.015, unlawful items in a prison or jail in 221.111, the sentence and fine limits in 558.011 and 558.002, the Criminal Code definition of deadly weapon in 556.061, the school discipline rules in 160.261, the gang weapon confiscation rules in 578.435 and 578.437, the Bi-State Development rules in 70.441 and the firearms preemption statute in 21.750. It does not cover city or county ordinances, federal property, tribal land, or the law of other states.

What Missouri law says about brass knuckles

Missouri lists knuckles among the weapons that a person may not deal with at all. Section 571.020 provides:

"1. A person commits an offense if such person knowingly possesses, manufactures, transports, repairs, or sells: ... (5) Knuckles;" RSMo 571.020.1(5)

The offense has no intent element and no requirement that the knuckles be concealed or used. Knowing possession is enough. Section 571.020.3 sets the class: "a crime pursuant to subdivision (4) or (5) of subsection 1 of this section is a class A misdemeanor."

How Missouri defines knuckles

The weapons chapter defines the term by what the item is built to do:

"(13) "Knuckles", any instrument that consists of finger rings or guards made of a hard substance that is designed or adapted for the purpose of inflicting serious physical injury or death by striking a person with a fist enclosed in the knuckles;" RSMo 571.010(13)

Three elements come out of that text: finger rings or guards, made of a hard substance, and designed or adapted to inflict serious physical injury or death by striking with an enclosed fist. The definition applies "as used in this chapter," meaning Chapter 571.

Plastic knuckles and knuckle knives

Because the definition turns on a "hard substance" rather than metal, plastic, composite or other non-metal sets that meet the other elements fall within it.

A knife with a knuckle guard is less clear. The definition covers an instrument "that consists of finger rings or guards," and the statute does not say how an item that combines a blade with a knuckle guard is treated. For the knife rules themselves, see our guide to Missouri knife laws.

Owning, buying and keeping brass knuckles

Section 571.020.1 reaches possession itself, so owning a set at home is an offense, and the statute does not carve out possession for self-defense or as a collector's item. Keeping knuckles in a car is possession, and driving them somewhere is transporting them; Missouri has no separate vehicle rule that changes this. Selling and repairing knuckles are listed acts as well.

Who is exempt

The exceptions are narrow and have two parts that must both be met. Section 571.020.2 reads:

"2. A person does not commit an offense pursuant to this section if his or her conduct involved any of the items in subdivisions (1) to (5) of subsection 1, the item was possessed in conformity with any applicable federal law, and the conduct: (1) Was incident to the performance of official duty by the Armed Forces, National Guard, a governmental law enforcement agency, or a penal institution; or (2) Was incident to engaging in a lawful commercial or business transaction with an organization enumerated in subdivision (1) of this section ; or (3) Was incident to using an explosive weapon in a manner reasonably related to a lawful industrial or commercial enterprise; or (4) Was incident to displaying the weapon in a public museum or exhibition; or (5) Was incident to using the weapon in a manner reasonably related to a lawful dramatic performance." RSMo 571.020.2

For knuckles, the relevant routes are official duty, a lawful business transaction with one of the listed organizations, a public museum or exhibition, and a lawful dramatic performance, and in each case the item must also be possessed in conformity with any applicable federal law. The list does not include self-defense, private collections or concealed carry permit holders.

Carrying brass knuckles in restricted places

Missouri's unlawful-use-of-weapons statute, section 571.030, does not name knuckles, but several of its subdivisions reach "any other weapon readily capable of lethal use." The statute does not say whether knuckles fall within that phrase, and that question should be treated as open. Section 571.030.1 provides that a person commits the offense if he or she knowingly:

"(1) Carries concealed upon or about his or her person a knife, a firearm, a blackjack or any other weapon readily capable of lethal use into any area where firearms are restricted under section 571.107; ... (8) Carries a firearm or any other weapon readily capable of lethal use into any church or place where people have assembled for worship, or into any election precinct on any election day, or into any building owned or occupied by any agency of the federal government, state government, or political subdivision thereof; ... (10) Carries a firearm, whether loaded or unloaded, or any other weapon readily capable of lethal use into any school, onto any school bus, or onto the premises of any function or activity sponsored or sanctioned by school officials or the district school board;" RSMo 571.030.1(1), (8), (10)

Under 571.030.8(2), a violation of subdivision (1) or (8) is a class B misdemeanor, except that when a concealed weapon is carried onto private property posted off-limits to concealed firearms with signs meeting the statute's size rules, the penalties of section 571.107.2 apply. The penalty for subdivision (10) in 571.030.8(3) is written around firearms: a class A misdemeanor "if the firearm is unloaded and a class E felony if the firearm is loaded." The statute does not say how that wording applies to a weapon other than a firearm.

These place-based subdivisions sit on top of the flat ban. Whether or not 571.030 reaches them, knuckles carried into a school, church or government building are still possessed in violation of 571.020.

Does a concealed carry permit help?

Section 571.030.4 provides that subdivisions (1), (8) and (10) "shall not apply to any person who has a valid concealed carry permit" issued under Missouri law, a valid pre-2013 endorsement, or a valid permit or endorsement "to carry concealed firearms" from another state. That exception is limited to those three subdivisions of 571.030. The knuckles offense in 571.020 has its own exception list, and a permit is not on it.

Threatening display

Section 571.030.1(4) makes it unlawful use of weapons to knowingly exhibit, "in the presence of one or more persons, any weapon readily capable of lethal use in an angry or threatening manner." Under 571.030.8(1), a violation of subdivision (4) is a class E felony. As with the place-based subdivisions, the statute does not name knuckles, and whether a given set counts as a weapon readily capable of lethal use is not settled by its text.

Schools

Missouri law names knuckles in its school discipline statute. Section 160.261.6 lists "a knife, knuckles, a machine gun, a projectile weapon, a rifle, a shotgun, a spring gun or a switchblade knife" among the weapons it covers. Under section 160.261.5, every district's discipline policy must provide for a suspension of not less than one year, or expulsion, for a student determined to have brought a weapon to school (including the school playground or parking lot), on a school bus, or to a school activity on or off school property. The superintendent (or, in a district with no high school, the principal) may modify the suspension case by case, and the district may still provide education in an alternative setting. School discipline is separate from any criminal charge. Criminally, the 571.020 ban has no place element, so it applies on school grounds, on school buses and on college campuses the same as anywhere else, and 571.030.1(10) may add a separate charge if knuckles are treated as a weapon readily capable of lethal use.

Jails and prisons

Bringing knuckles to a jail or prison is a felony. Under section 221.111.1(4), a person commits the offense of possession of unlawful items in a prison or jail by knowingly delivering, attempting to deliver, possessing, depositing or concealing "any gun, knife, weapon, or other article" that may endanger the institution's safety or security, or the life or limb of a prisoner or employee, in or about the premises of a state correctional center or any city, county or private jail. Under 221.111.2, that is a class B felony, punishable by 5 to 15 years in prison under section 558.011.1(2).

Felony records and other definitions

Missouri's felon-in-possession statute, section 571.070.1, is written for firearms: a person commits the offense "if such person knowingly has any firearm in his or her possession" after a qualifying conviction. It does not mention knuckles. A person with a felony record is still subject to the class A misdemeanor in 571.020 like anyone else.

Knuckles also appear in other parts of the code:

• Deadly weapon. The Criminal Code definition in section 556.061(22) defines "deadly weapon" as any firearm, any weapon from which a shot readily capable of producing death or serious physical injury may be discharged, "or a switchblade knife, dagger, billy club, blackjack or metal knuckles." That definition says "metal knuckles," a narrower phrase than the hard-substance definition in 571.010(13). It matters most if knuckles are used in a crime: under section 571.015.1, a person who commits any felony with a deadly weapon or dangerous instrument is also guilty of armed criminal action, punishable by 3 to 15 years in prison, served consecutively to the sentence for the underlying felony, with no parole, probation, conditional release or suspended sentence for three calendar years. Second and later offenses carry higher minimums under 571.015.2 and .3.
• Gang-related confiscation. Section 578.435.1 includes "knuckles" as defined in section 571.010 in the weapons covered by that section and section 578.437. Under 578.435.2, a weapon owned or possessed by a criminal street gang member for the purpose of committing a listed gang offense may be confiscated by law enforcement, and if a court declares it a nuisance, it is destroyed. Section 578.437 requires reasonable notice to the lawful owner before a weapon is declared a nuisance.
• Bi-State Development facilities. Section 70.441.3(11), part of the rules for Bi-State Development transit facilities and conveyances, bars carrying a weapon, including "metal knuckles," in or on any facility or conveyance, except for law enforcement personnel and an unloaded rifle or shotgun carried in a case that completely conceals it. Unless state law provides a greater penalty, a violation of section 70.441 is a misdemeanor with a fine of $25 to $250 per violation under 70.441.4(1).

Minors

Missouri has no separate statute on selling or giving knuckles to minors. The 571.020 offense applies to any person who knowingly possesses, transports, repairs or sells knuckles, with no age limit and no age-based exception, so it reaches a minor who possesses a set and an adult who sells one.

Penalties

Whether the 571.030 rows reach knuckles depends on whether a set is "readily capable of lethal use," which the statute does not resolve. Section 558.002.1 sets the fine for a class A misdemeanor at up to "two thousand dollars," or, if the person gained money or property through the offense, an amount "not exceeding double the amount of the person's gain." Under section 558.011.1, a class A misdemeanor carries a jail term of up to one year, a class B misdemeanor up to six months, and a class E felony up to four years in prison. Under section 558.002.1, the maximum fine is $1,000 for a class B misdemeanor and $10,000 for a class E felony.

City and county rules

Missouri's preemption statute, section 21.750.1, occupies "the entire field of legislation touching in any way firearms, components, ammunition and supplies." Its text does not mention knuckles. Section 21.750.3(1) also allows local ordinances that conform exactly with sections 571.010 to 571.070, which include the knuckles ban, with appropriate penalty provisions. Check your city or county code, or call your local police department's non-emergency line, about any local rule.

Self-defense alternatives under Missouri law

Because knuckles are banned for private citizens, readers looking for protection often compare other options. The rules for sprays and stun devices are in our guide to Missouri pepper spray and stun gun laws, and the rules on when force may be used at all are in Missouri self-defense laws.

Related pages

• Brass knuckles laws by state
• Missouri knife laws
• Missouri pepper spray and stun gun laws
• Missouri self-defense laws

This article provides general legal information about Missouri state law, not legal advice. Weapons laws change and local rules vary. For advice about a specific situation, contact a lawyer licensed in Missouri or your local law enforcement agency.

Last updated: 2026-10-08.

Frequently Asked Questions

Are brass knuckles legal in Missouri?

No. RSMo 571.020.1(5) makes it an offense to knowingly possess, manufacture, transport, repair or sell knuckles, and 571.020.3 classes it as a class A misdemeanor, with narrow exceptions for official duty, related business transactions, museums and dramatic performances.

Can I keep brass knuckles at home in Missouri?

Missouri's knuckles offense covers knowing possession anywhere, and the exceptions in 571.020.2 do not include possession at home or for self-defense.

Are plastic brass knuckles legal in Missouri?

Section 571.010(13) defines knuckles as finger rings or guards made of a hard substance designed or adapted to inflict serious physical injury or death by striking, so the definition does not require metal. A plastic or composite set that meets that description falls within the definition, and possessing it is a class A misdemeanor under 571.020.

What is the penalty for brass knuckles in Missouri?

Possessing, manufacturing, transporting, repairing or selling knuckles is a class A misdemeanor under 571.020.3. The fine for a class A misdemeanor can reach $2,000 under 558.002.1(2), or up to double the offender's gain under 558.002.1(7), and the jail term can reach one year under 558.011.1(6).

Does a Missouri concealed carry permit cover brass knuckles?

No. The permit exception in 571.030.4 applies only to subdivisions (1), (8) and (10) of the unlawful-use-of-weapons statute, and the knuckles offense in 571.020 has no permit exception at all.

Can I keep brass knuckles in my car in Missouri?

Missouri has no separate vehicle rule for knuckles. Section 571.020.1 makes it an offense to knowingly possess or transport them, so keeping a set in a car falls within the same class A misdemeanor.

Can I buy brass knuckles online and have them shipped to Missouri?

Section 571.020.1 makes it an offense to knowingly possess or transport knuckles in Missouri, so receiving and keeping a set falls within the class A misdemeanor unless one of the narrow 571.020.2 exceptions applies.