Switchblades may look like something out of an action movie, but in California, they’re more than just flashy tools — they’re a legal minefield. Many people don’t realize that simply carrying or even having a switchblade in your car could lead to criminal charges. Whether you’re a knife enthusiast, a collector, or someone who just bought one out of curiosity, understanding California Penal Code § 21510 PC is absolutely essential.
This law doesn’t just target people using knives for crimes; it also applies to ordinary citizens who unknowingly break the rules. One wrong move — like having a switchblade in your pocket or glove box — can result in an arrest, fines, or even jail time.
This guide will walk you through everything you need to know about California’s switchblade laws, including the legal definition, what conduct is prohibited, possible penalties, common defenses, and practical tips to avoid trouble. By the end, you’ll know exactly what the law allows and what it doesn’t — and what to do if you ever find yourself facing a charge under § 21510 PC.
What Does California Penal Code § 21510 PC Say?
California Penal Code § 21510 makes it a misdemeanor offense to do any of the following with a switchblade knife that has a blade two inches or longer:
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Possess the knife in the driver’s or passenger’s area of any motor vehicle in a public place or a place open to the public.
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Carry the knife on your person (in a pocket, waistband, or bag).
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Sell, offer for sale, expose for sale, loan, transfer, or give the knife to another person.
This means you don’t have to use the knife, threaten someone, or even have bad intentions. Just having it on you or accessible in your vehicle can be enough for a criminal charge.
The law is designed to reduce the potential for violence and protect public safety by limiting access to knives that can be quickly opened and used as weapons.
What Exactly Is a “Switchblade”?
To understand whether a knife is legal or not, you have to look at how the law defines a switchblade. Under California law, a switchblade is:
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A knife that appears to be a folding pocketknife,
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Has a blade two inches or longer, and
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Opens automatically by pressing a button, applying pressure to the handle, flipping the wrist, or by the weight of the blade itself.
In short, if a knife opens automatically or with minimal effort from a built-in mechanism, it’s probably a switchblade.
Knives That Count as Switchblades
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Automatic knives that open with the push of a button or lever.
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Gravity knives that open due to the weight of the blade.
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Butterfly or balisong knives that flip open through a mechanical motion.
Knives That Are Not Considered Switchblades
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Traditional folding knives that open manually with thumb pressure or a thumb stud.
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Knives that have a “bias toward closure,” meaning they resist opening until manual pressure is applied.
The key difference lies in how the knife opens. If it opens automatically without significant manual force, California law treats it as a switchblade.
What Actions Are Prohibited Under § 21510 PC?
California Penal Code § 21510 PC focuses on where and how you have the knife. You can violate this law in several ways:
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Carrying a switchblade on your person – Keeping one in your pocket, clipped to your belt, or in a backpack you’re wearing counts as “carrying.”
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Having a switchblade in your vehicle – Even if it’s not on your body, having it accessible in the driver or passenger area (like the glove box, console, or under the seat) is illegal.
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Selling or giving a switchblade to someone else – It’s against the law to sell, offer, loan, or gift a switchblade with a blade two inches or longer.
Importantly, the prosecution doesn’t have to prove you intended to use the knife as a weapon. Merely having it in a prohibited place or giving it to someone else can lead to a misdemeanor charge.
Penalties for Violating § 21510 PC
A conviction for possessing a switchblade under § 21510 PC is a misdemeanor. The potential penalties include:
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Up to 6 months in county jail
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A fine of up to $1,000
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Summary probation (informal probation), often granted for first-time offenders
Even though it’s a misdemeanor, a conviction can still show up on your criminal record and cause problems when applying for jobs, professional licenses, or even housing. For this reason, taking these charges seriously is crucial.
Defenses to a Switchblade Charge
Just because you were arrested doesn’t mean you’ll be convicted. There are several legal defenses that may apply to your case.
1. The Knife Wasn’t a Switchblade
If your knife opens manually and doesn’t meet the legal definition of a switchblade, then § 21510 PC doesn’t apply. Many modern pocketknives use assisted-opening mechanisms that still require manual force, which may be exempt.
2. Lack of Knowledge
You must “knowingly” possess or carry the knife. If someone else placed it in your car or bag without your knowledge, you may not be guilty.
3. Illegal Search or Seizure
If police found the knife during an unlawful search — without probable cause or a valid warrant — your attorney can challenge the evidence and possibly have it suppressed in court.
4. Private Ownership
In some cases, keeping a switchblade at home (without carrying or displaying it in public) may not violate § 21510 PC. The statute specifically prohibits possession in vehicles and public places, not private ownership inside your residence. However, other local or federal rules may still apply.
Practical Tips to Avoid Violating California Knife Laws
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Know your knife. Measure the blade length and understand how it opens. If it opens automatically with minimal effort, don’t carry it in public.
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Avoid storing it in your car. Even if it’s just for transport, having a switchblade in the driver or passenger area can be enough for an arrest.
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Don’t sell or gift a switchblade. Transferring one, even as a gift, can trigger criminal liability.
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Keep documentation. If you’re a collector, keep proof that the knife is for display only and not carried for use.
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When in doubt, leave it at home. Carrying or transporting knives in California can be confusing — when unsure, err on the side of caution.
Related Knife Laws in California
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Penal Code § 21310 PC: Prohibits carrying concealed dirks or daggers.
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Penal Code § 16590 PC: Bans specific “generally prohibited weapons,” which may include certain knife types.
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Local ordinances: Some cities, like Los Angeles and San Francisco, have stricter local regulations on knives and blade lengths.
Always check both state law and local laws before carrying or transporting any type of knife.
Example
Imagine a motorist pulled over for a routine traffic stop. The officer sees a knife clip in the driver’s pocket and asks to inspect it. The knife turns out to be an automatic-opening model with a 3-inch blade.
Even if the driver had no intent to harm anyone, that’s still a violation of § 21510 PC because it meets the definition of a switchblade and was accessible in the vehicle’s passenger area. The driver could face arrest, fines, and a misdemeanor charge — all from a simple oversight.
Why Legal Help Matters
California’s knife laws can be surprisingly complex. Many defendants charged under § 21510 PC are ordinary people who didn’t realize their knife was illegal. An experienced criminal defense lawyer can help by:
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Reviewing whether the knife truly qualifies as a switchblade,
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Determining if the police conducted a lawful search, and
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Negotiating for dismissal, diversion, or reduced charges.
If you’re facing charges or have been arrested for possessing a switchblade, don’t try to handle it alone. Legal guidance can make the difference between a permanent criminal record and a cleared name.
Conclusion
California Penal Code § 21510 PC makes it illegal to carry, possess in a public vehicle, or sell a switchblade knife with a blade two inches or longer. While the law aims to keep the public safe, it often catches well-meaning people who simply didn’t know the rules.
Knowing the definition of a switchblade, where you can and can’t carry it, and how to handle it responsibly can protect you from unnecessary legal trouble. If you’re ever unsure about your rights or if you’ve been charged under this law, professional legal help is your best defense.
Call to Action
If you’ve been arrested or are under investigation for possession of a switchblade under California Penal Code § 21510 PC, don’t wait. The right defense strategy can protect your freedom and your future. Contact us today — our experienced criminal defense team knows how to fight these cases and get results. Call Southwest Legal now for a free and confidential consultation.
