8 Must-Know Legal Facts About “Carrying A Switchblade”

Penal Code Section 21510

A switchblade1 is a serious and deadly weapon. Possession of one under any circumstances is a criminal violation under Penal Code Section 21510.

Below are 8 must know legal facts about how California treats this crime.

Overview Of Penal Code 21510 PC

PC 21510 makes it clear that it is illegal to possess or carry a switchblade under the following circumstances:

  • Carry the switchblade upon your person
  • To sell or offer to sell or expose it for sale, or loan a switchblade to anyone2
  • Possess the knife in the driver or passenger side of a motor vehicle while in a public place or place open to the public3

Possession of a switchblade is unlawful but there are elements of the crime that the DA must prove beyond a reasonable doubt:

  • You had knowledge or were aware that you were carrying or possessing a switchblade
  • On your person or in your car
  • And you knew that it fit the legal definition of a switchblade or had the characteristics of one

Possessing the weapon means that you had control over it. It only has to be in your jacket or coat or in a handbag and you were aware of its presence4.

Definition Of A Switchblade

To be convicted of carrying or possessing a switchblade, the knife must fit the legal definition:

  1. A knife with the appearance of a pocketknife
  2. With a blade or blades that is at least 2 inches in length
  3. That can be released automatically by flicking your wrist, pressing a button or applying pressure on the handle or by any other type of release mechanism

Are there Other Knives that Fit the Description of a Switchblade?

Other knives that fit the legal description of a switchblade are

  • Gravity knives5.
  • Spring blades and Springer or snap blade knives6.
  • Butterfly or batanga knives are also illegal as they are folding pocket knives7.
  • Ballistic knives are in a special category under PC 16220 and 21110.

However, certain knives that closely resemble switchblades are not included and are exceptions to this code section. These are:

  1. A knife that opens with one hand where thumb pressure is applied solely to the blade, or
  2. To a thumb stub attached to the blade and,
  3. So long as the knife has some mechanism such as a detent that provides resistance in opening the blade or biases the blade back to its closed position8

What is a Detent?

A detent is a mechanism or catch that prevents motion or resists it until released by applying force to one of its parts.

Are pocket knives legal?

Most pocket and folding knives are not switchblades, however, it is illegal to carry any of these if the knife is in public view and is in a locked position.

Defenses To Carrying Or Possessing A Switchblade

The Weapon is not a Switchblade

One of the major defenses if you are suspected of violating PC 21510 is that the knife lacks the characteristics of a switchblade. If it has a detent or offers resistance to opening it, it is not a switchblade though it may resemble one to most persons.

If it has any kind of device or mechanism that offers resistance to opening it, then it fails to come under this code section and is legal to carry so long as it is not open and in a locked position9.

Lack of Knowledge of its Presence

If you can show that you had no knowledge the switchblade was in your jacket or bag you were holding or in the car you were driving, then this element of the offense is lacking10.

Though the burden of proof is on the prosecution, you will have to offer some evidence that the jacket, coat, bag or car belonged to someone else and you were borrowing it, or that someone else had been in possession of it before you possessed it or were detained by law enforcement.

If you knew you were carrying a knife, the DA does have to prove you knew it was a switchblade or fit the legal definition of one.

Illegal Search and Seizure

You cannot be detained or told to offer yourself or vehicle to be searched absent a search warrant or probable cause to perform the search by a law enforcement or peace officer.

The officer must have a reasonable suspicion or evidence that you committed a crime or were about to commit one. If you are stopped for a traffic violation, absent probable cause the officer has no right to search you or your car unless you consent or you assault or attempt to assault the officer and are arrested.

If you are arrested, the officer can search you incident to the arrest. Even if a search warrant is issued, it is invalid if based on an officer’s fabrication of probable cause or if the search exceeded the scope of the warrant.


Violation of PC 21510 is a misdemeanor11 with the following possible penalties:

  • County jail time of up to 6 months
  • And/or a fine up to $1000
  • Or summary probation with or without jail time

Jail time is likely if any of the following aggravating circumstances occur:

If you were carrying a ballistic knife, which is a type of spring load knife, you are committing a misdemeanor though the possible county jail time is up to one year instead of 6 months.


Expungement of your conviction under PC 21510 is possible since this violation is a misdemeanor and does not include serving time in state prison, the main determining factor in whether you can expunge a conviction.

Expungement12 is offered under PC 1203.4. Although a misdemeanor conviction does not carry the ignominy and serious obstacles to finding suitable employment, housing or qualifying for public benefits or denial of your Second Amendment right to own or possess a firearm if convicted of a felony, you will want to seek an expungement since your conviction will not appear on any public database.

  • Find Out if You Are Eligible To Have Your Record Expunged
  • Stop Worrying About Employer Background Checks
  • Stop Worrying About Landlord Background Checks

Related Offenses

Next Steps

If you have been arrested and would like to learn more about how attorneys charge.

If you want to understand why its important to have an attorney represent you.

If you would like to discuss a pending case for carrying a switchblade with an attorney contact the Aizman Law Firm at 818-351-9555 for a free confidential consultation.

Get Legal Help

Request A Free Consultation 818-351-9555 


  1. California Criminal Jury Instruction No 2502 – A switchblade knife is a knife that looks like a pocketknife and has a blade that can be released automatically by a flick of a button, pressure on the handle, flip of the wrist or other mechanical device, or is released by the weight of the blade or any other mechanism. A switchblade includes a spring-blade knife, snap-blade knife, gravity knife, or any other similar type knife. A switchblade knife does not include a knife that opens with one hand utilizing thumb pressure applied solely to the blade of the knife or a thumb stud attached to the blade, if the knife has a detent or other mechanism that provides resistance that must be overcome in opening the blade or that biases the blade back toward its closed position []
  2. California Penal Code 21510 PC – Every person who does any of the following with a switchblade knife having a blade two or more inches in length is guilty of a misdemeanor []
  3. On the meaning of “public place,” see In re Danny H. (2002) 104 Cal.App.4th 92, 98 [128 Cal.Rptr.2d 222], discussing the meaning of public place in Penal Code section 594.1 []
  4. People v. Azevedo (1984) 161 Cal.App.3d 235, 243-243 []
  5. California Penal Code 17235 []
  6. California Penal Code 17235 []
  7. Butterfly and Tekna knives are prohibited switchblades under Penal Code section 17235 [formerly section 653k]. (People ex rel. Mautner v. Quattrone (1989) 211 Cal.App.3d 1389, 1395 [260 Cal.Rptr. 44]. []
  8. In re Gilbert R., G045929; []
  9. Broken Spring Knife- Where the spring mechanism on the knife did not work, the court found insufficient evidence that the knife was a prohibited switchblade under Penal Code section 17235 [formerly section 653k]. (In re Roderick S. (1981) 125 Cal.App.3d 48, 52 [177 Cal.Rptr. 800]. []
  10. Knowledge Required. See People v. Rubalcava (2000) 23 Cal.4th 322, 331–332 [96 Cal.Rptr.2d 735, 1 P.3d 52] []
  11. California Penal Code 21510 – Every person who does any of the following with a switchblade knife having a blade two or more inches in length is guilty of a misdemeanor: (a) Possesses the knife in the passenger’s or driver’s area of any motor vehicle in any public place or place open to the public. (b) Carries the knife upon the person. (c) Sells, offers for sale, exposes for sale, loans, transfers, or gives the knife to any other person. California Law []
  12. Penal Code 1203.4 []

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