Brass knuckles are illegal in California. Under Penal Code 21810, owning them, selling them, lending them, or bringing them into the state is a criminal offense, and prosecutors can file the charge as either a misdemeanor or a felony.1California Legislative Information. California Penal Code 21810 – Metal Knuckles Penalties run from up to a year in county jail on the low end to a three-year sentence on the high end, and a conviction can cost you your firearm rights.
What Counts as Brass or Metal Knuckles
The statute uses the term “metal knuckles,” and Penal Code 16920 defines them as any device made wholly or partially of metal, worn on or over the hand, that either protects the wearer’s hand during a punch or increases the force delivered to the person struck.2California Legislative Information. California Penal Code 16920 – Metal Knuckles The definition is deliberately broad. It covers the classic four-finger brass set, but also any metal hand device intended for offensive or defensive use, including items with metal studs, projections, or a metal shield over the fist.
“Wholly or partially of metal” is the material threshold. A device made from composite resin, carbon fiber, or hardened plastic bonded with metal components still qualifies because it is partially metal. A purely non-metal item, such as rubber novelty knuckles or a plastic costume prop, does not meet the statutory definition.2California Legislative Information. California Penal Code 16920 – Metal Knuckles If the item contains no metal, prosecutors cannot charge it under this statute. Using any hard object to strike someone could still support an assault charge regardless of material.
Penalties for Possession
Penal Code 21810 is a “wobbler,” meaning the prosecutor decides whether to file it as a misdemeanor or a felony.1California Legislative Information. California Penal Code 21810 – Metal Knuckles The choice usually turns on the arrest circumstances and the defendant’s record. Someone with no history caught with knuckles in a backpack will likely face a misdemeanor. Someone with prior convictions, or someone carrying them during another offense, is more likely to see a felony filing.
Misdemeanor
A misdemeanor conviction carries up to one year in county jail, a fine of up to $1,000, or both.1California Legislative Information. California Penal Code 21810 – Metal Knuckles3California Legislative Information. California Penal Code 19 – Misdemeanor Punishment A first-time offender without aggravating factors often receives probation instead of jail. Courts have wide discretion, and the facts of the discovery matter.
Felony
As a felony, the sentencing range is 16 months, two years, or three years under Penal Code 1170(h). That sentence is generally served in county jail rather than state prison, unless the defendant has a prior serious or violent felony, is a registered sex offender, or falls into another category the statute specifies.4California Legislative Information. California Penal Code 1170 – Determinate Sentencing A felony conviction also creates a permanent criminal record that surfaces on background checks, affecting employment, housing applications, and professional licensing.
Additional Charges if the Knuckles Are Used
Possession is a standalone offense, but using metal knuckles to hurt someone brings much heavier exposure. They can qualify as a deadly weapon under California law, so striking someone with them can support a charge of assault with a deadly weapon under Penal Code 245(a)(1), which carries up to four years in state prison.
The possession charge does not merge into the assault charge. Prosecutors regularly file both. Someone who punches another person while wearing metal knuckles can face a felony assault charge and a separate weapons-possession charge at the same time, each with its own potential sentence.
Who Is Exempt
Penal Code 21810 carves out a narrow set of exemptions that apply only to certain institutions and job functions:
- Federal, state, and local law enforcement agencies for official use, and peace officers on duty when authorized by their agency.1California Legislative Information. California Penal Code 21810 – Metal Knuckles
- Public museums, historical societies, and institutional collections, if the items are properly housed and secured.
- Authorized participants in movie, TV, or video productions during the course of that production.
- Forensic laboratory personnel within the scope of their authorized work.
Private collectors are not on that list. A common misconception holds that you can legally keep brass knuckles at home as a display piece or historical artifact. You cannot. Unless you meet one of the statutory exemptions, possession for “collecting” or “display” is still illegal. This catches people off guard, especially those who inherit items or buy them online from out-of-state sellers.
Common Defenses
The most practical defense in many cases is lack of knowledge. If metal knuckles turn up in a shared car, a borrowed bag, or a roommate’s closet, the prosecution must prove the defendant was aware of the item and had control over it. This defense comes up frequently in traffic-stop cases where the knuckles belonged to a passenger or a previous occupant.
A related defense challenges whether the object meets the statutory definition at all. An item with no metal in it falls outside Penal Code 16920.2California Legislative Information. California Penal Code 16920 – Metal Knuckles Decorative belt buckles shaped like knuckles, plastic novelty items, and rubber gag versions have all been disputed on this ground. Material composition and functional capability are what count.
Temporary or momentary possession is also a recognized defense. If you picked up someone else’s brass knuckles to move them, dispose of them, or keep someone else from using them, with no intent to keep or use them yourself, that context can undermine the prosecution’s case. Courts look at how long you had the item and what you were doing with it.
Firearm Rights and Air Travel
A felony conviction under Penal Code 21810 costs you the right to own or possess firearms in California. That prohibition is permanent unless you obtain relief through expungement or by reducing the felony to a misdemeanor. Because 21810 is a wobbler, a defendant convicted of the felony can petition the court to reduce the offense to a misdemeanor after completing probation, which would restore firearm rights.
Air travel is the other trap. The TSA allows metal knuckles in checked baggage but prohibits them in carry-on.5Transportation Security Administration. What Can I Bring? The TSA itself notes that these items remain illegal in some states. Flying into California with brass knuckles in checked luggage means you are in possession of a prohibited weapon the moment you land and collect your bag. Ignorance of California law is not a defense, and this scenario does lead to arrests.