Let's say I'm driving down a major interstate highway and I see a group of ~100 or so people climbing over the highway fence and spilling out onto the highway. They have signs, so I'm going to assume they're protestors and I bring my vehicle to a stop. Half an hour goes by, and the protestors are still blocking the road.

I lose my patience and start yelling inflammatory comments out the window ("Get the f*ck out of the road!"). The protestors surround my car and start banging on the windows/car. I'm getting anxious.

My car happens to be equipped with a tear gas release system which can blast a cone of tear gas through the front of the car and I have a gas mask. Aside from my car smelling terrible for a few days, what are the (legal) consequences of deploying said system in an attempt to get the protestors off my car?


2 Answers 2


You have to pick a jurisdiction: I pick California. Cal. Penal 22810 says that

Notwithstanding any other provision of law, any person may purchase, possess, or use tear gas or any tear gas weapon for the projection or release of tear gas if the tear gas or tear gas weapon is used solely for self-defense purposes, subject to the following requirements

The list of requirements that follow include not being a felon, drug addict or minor. It has to be under 2.5 ounces and dispensed as spray, and if you use it for purposes other than self defense, it is a crime in its own right. Your description of the delivery system is not explicit enough that we can guess whether this is an "aerosol spray", so I will assume it is.

Is it justified as self defense? This will tell you. I assume based on your description that you have a reasonable belief that you are in imminent danger of bodily harm. You did not use excess force. You are not required to retreat. But this also is relevant: by insulting the protestors, have you lost your right to self defense? Did you provoke a fight intending to create an excuse to use force? If so, you don't have the right to self defense. Telling a person to get out of your way is not generally held to be assault or initiating a fight, and doesn't fall in the category of "threat", but throwing the first punch is. Given the circumstances as described (and interpreted most favorably to you), you would be allowed to use tear gas in self defense.

  • 1
    @Trish you expressing your opinion based on the evidence which you present. This isn't the purpose of this site. The poster explicitly cited the relevant law. The purpose of this site is to ask questions which allow people to learn what the law happens to be. It is not to create a discussion forum on what the law should be.
    – grovkin
    Jun 10, 2020 at 18:21
  • @grovkin I believe the 2nd prong of regaining self-defense after starting the fight does not apply for the conduct described - and all cars that have such devices built in pretty much need an RPG to bust them open. There is no threat to him, he did not retreat from the fight. That voids any claim of self-defense.
    – Trish
    Jun 10, 2020 at 19:26
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    @Trish RPG may have been suggested by the question, but the answer makes it clear that it discusses a somewhat different arrangement. An aerosol is legal to own. Hand-held "pepper spray" aerosols are commonly sold and do not require a license to own or carry. The answer only deals with installing a similar device in a car. The significance of the difference is that an aerosol cannot, for example, cause a blunt force trauma when properly used. The answer only deals with what the law is. I don't see any problem with such an answer and I think it is completely in line with the site's intent.
    – grovkin
    Jun 10, 2020 at 23:38
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    @Trish (1) your objection to any use of teargas as such is an objection to the law allowing such use. This answer cited the relevant law. Again discussing what the law should be is not what this site does. It only gives a chance for people to ask what the law happens to be. (2) Whether or not someone is safe in the car is a decision on the facts... not on the law. The answer is given with the assumption that the facts are as close as possible to what is stated in the question. Namely, the answer describes what the law prescribes in a situation when someone is not safe.
    – grovkin
    Jun 11, 2020 at 1:25
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    @Trish not only did not "deliberately" overlook that point, but I did not overlook that claim at all. I addressed it directly in point (2).
    – grovkin
    Jun 11, 2020 at 23:20

Let's look at the legality of Teargas first. And I am going to go Hard with you and drag you to the worst courts:

Military/PMC car?!

If you are in the military, then you can't possess it at all legally as that alone would break the Chemical Weapon Convention - and using it against civilians, even protesting ones rocking your car would break all kinds of laws. Nope, your car is armed with an illegal substance (fr the military) as an irritant is counted as a chemical weapon for the military, so you can NOT use it, and you might end in front of a military tribunal for its use or, in another country, in Den Hague as a war criminal if you use it. If you are a civilian of a PMC in a warzone, you might get charged as an illegal combatant above that!

New York

Let's put you to New York... and you are in hot water, because your device is not pocket sized, making the dispersion mechanism illegal and thus your use of it use of an illegal weapon:

PEN § 265.20 14. (a) As used in this section “self-defense spray device” shall mean a pocket sized spray device


Let's go to California. You may have your tear gas car there, but you might not be able to use it as you wanted... because to be able to act in self-defense you need to be

  1. The defendant reasonably believed that (he/she/ [or] someoneelse/[or] [insert name or description of third party])was in imminent danger of being killed or suffering great bodily injury [or was in imminent danger of being(raped/maimed/robbed/ [insert other forcible and atrocious crime])];

  2. The defendant reasonably believed that the immediate use of deadly force was necessary to defend against that danger;


  1. The defendant used no more force than was reasonably necessary to defend against that danger. CALCRIM No.505

You'd need to prove "imminent danger of being killed or suffering great bodily injury" - you are sitting in a car and the car gets pushed up and down - because if your car has a defense system of that caliber, your car is most likely armored and nothing but its paint job is in danger but for an RPG or blowtorch. The crowd might make you anxious, but it does not put you at danger, nobody has pulled out a handgun to even attempt to threaten you (and possibly ricochet into the crowd), nobody has pulled out a baseball bat to hammer upon your car. The crowd does not really provide a threat to you but for the vehicle, and even worse, the situation was brought to be this by the action of OP who riled up the crowd. And as we are not at homicide, we must look at self defense in what is the closest.. and I think that might be self-defense in combat. But, oh shock, OP did start the fight, and he did not in good faith stopped fighting and expressed so verbally and by conduct in a way that a reasonable person would understand that he wanted to stop fighting.

A person who (engages in mutual combat/ [or who] starts a fight) has a right to self-defense only if:

  1. (He/She) actually and in good faith tried to stop fighting;[AND]

  2. (He/She) indicated, by word or by conduct, to (his/her) opponent, in a way that a reasonable person would understand, that (he/she) wanted to stop fighting and that (he/she) had stopped fighting(;/.) CALCRIM No.3471

The second prong was given up by OP, so he did not regain the right of self defense: he lacked proper expression of their retreat from the fight he started to the people he incited. So he does not have the right of self-defense, even worse, he could be charged for inciting a riot as OP "urged others to commit acts of force or violence" against him "at a time and place and under circumstances that produced a clear, present, and immediate danger" of riot and creating danger for him - the third prong of OP intending to cause a riot would be the hardest leg to prove for the state.


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