What would be considered as a true threat? What is considered to be as a true threat? Let's say that there is a person who said to someone else "You deserve to die... Watch your back, I'm coming for you." which becomes an issue in court. On what grounds and argument would the Prosecution use to argue that this was a true threat and what grounds or argument would the defense argue that this was not a true threat?
The only meaningful discussion from the Supreme Court of what constitutes a "true threat" comes from Virginia v. Black, 538 U.S. 343, 359 (2003): “True threats” encompass those statements where the speaker means to communicate a serious expression of an intent to commit an act of unlawful violence to a particular individual or group of individuals. ... The speaker need not actually intend to carry out the threat. Rather, a prohibition on true threats “protect[s] individuals from the fear of violence” and “from the disruption that fear engenders,” in addition to protecting people “from the possibility that the threatened violence will occur.” Ibid. Intimidation in the constitutionally proscribable sense of the word is a type of true threat, where a speaker directs a threat to a person or group of persons with the intent of placing the victim in fear of bodily harm or death. A few other courts have elaborated further: A true threat is a communication that, when taken in context, “would have a reasonable tendency to create apprehension that its originator will act according to its tenor.” United States v. Martinez, 736 F.3d 981, 986 (11th Cir. 2013). A “true threat” is defined as a “statement that a reasonable recipient would have interpreted as a serious expression of an intent to harm or cause injury to another.” United States v. Mabie, 663 F.3d 322, 330 (8th Cir. 2011). As far as I know, the Ninth Circuit is the only circuit to conclude that a speaker must intend his communication to be threatening. Most courts find it sufficient to show only that the speaker intended to make the communication, and that a reasonable person would feel threatened by it. If your hypothetical were in court, the debate would be about the two questions above. Since it doesn't sound like there's any question that you meant to make the statement, most of the debate would focus on whether a reasonable person would feel threatened by your statement. The prosecution would ask the victim about the background of your relationship, what you said, what your demeanor was, and what the victim understood the statement to mean, and then the prosecutor would argue that in the context in which the statement was made, any reasonable person would fear being harmed. Your defense attorney would try to minimize the seriousness of the statement, demonstrate that you never followed through (though this may not be relevant), suggest that the statement wasn't serious and wasn't intended to be serious, and that no one could believe you honestly intended to hurt the victim. From there, would be up to the jury to decide who it believes.
If an adult had physically restrained the miscreant brat, they could be sued for / charged with battery (which does not mean "beating up", per Cal Penal 242, it is the "willful and unlawful use of force or violence upon the person of another". In either case, there is a defense that can be mounted, the "defense of others" defense, to the effect that the person had a reasonable belief that it was necessary to prevent physical harm to others. Which means, the jury would imagine themselves in that situation and guess how likely it is that someone might get hurt. Lofting 5 lb chess pieces at a 2 year old could poke out an eye, especially since they haven't learned to duck at that age – however, I question (as would an opposing attorney) the characterization "quite dangerous". At any rate, it would depend on the level of danger posed. There is also a "proportionality" requirement for the defense of others defense: "The defendant used no more force than was reasonably necessary to defend against that danger" (CalCrim instruction 3470). The battery might not have been necessary, since simply getting between the criminal and his victims could have been sufficient. As to whether there would actually be a lawsuit, that depends in part on the mind-set of the parents. Assuming that the level of force did not rise above simple bodily contact, it is unlikely that a jury would vote to convict / find liable, but certainly not impossible. If under those circumstances the results would not be in serious doubt, then it is unlikely that the person would be prosecuted (the prosecutor wouldn't bother with such a case). We may also assume that a decent attorney would persuade the offended parent-client that it is not a good use of their money to pursue he matter. Still, the risk is not negligible, since you don't know whether you'll have bad luck with the jury, or whether the child suffers from eggshell skull syndrome and then you would be is serious trouble. I don't think the fears are unrealistic, though they may be improbable, and they could be definitive for people who live in fear.
Does castle doctrine mean any guest at a house can kill uninvited guests? No. You have a completely faulty reading of the Castle doctrine (Wikipedia). The Castle doctrine allows a person... protections and immunities permitting one, in certain circumstances, to use force... And, those circumstances: Castle doctrines lessen the duty to retreat when an individual is assaulted within one's own home. Deadly force may either be justified... "when the actor reasonably fears imminent peril of death or serious bodily harm to him or herself or another"... While Castle doctrines may not provide civil immunity, such as from wrongful death suits, which have a much lower burden of proof. Aspects of the castle doctrine vary according to jurisdiction.
The General Rule In practice, the only time when self-defense against a police officer is legal is when you do not know and have no reasonable way that you could have known that the person attacking you is a police officer. (And arguably, a police officer acting in an official capacity in furtherance of his or her duties, rather than in a personal capacity as an individual.) For example, if the police do a no knock raid in the dark of night, and don't announce themselves, and you shoot police officers reasonably believing them to be home invasion burglars, you would not have criminal or civil liability for doing so. A similar valid self-defense claim might arise when someone has an objectively reasonable reason to think that someone claiming to be a police officer is really just a criminal impersonating a police officer, even if that belief is, in fact, mistaken. In almost all other circumstances, you need to submit to the officers, and you are pretty much required by law to bear the risk that excessive force by the officer will harm you. If you don't, you will probably be guilty of the crime of resisting arrest and will not be entitled to a self-defense defense. The fact that you are not actually guilty of a crime is irrelevant. This is often the case and police officers are not omniscient. If the officer lacked probable cause for an arrest (which there is often no way that the person being arrested or attacked can know at the time), the remedy is a civil rights suit after the fact, not self-defense. In theory, there might be other isolated circumstances where self-defense against a police officer is legal, but they involve fact patterns so quirky that they would almost never happen in real life, or would almost never be possible to prove in a manner that the courts would believe. Officer Liability For Harming Someone Legitimately Acting In Self Defense Whether the officers had civil liability to you if you were harmed by the officers while exercising your right to self-defense would depend upon their state of mind, even if you were rightfully using self-defense. For example, a U.S. Supreme Court case decided in January of 2017 (White v. Pauly) involved this fact pattern. In White v. Pauly an officer arrived late on the scene and had no reason to believe that the officers who arrived there before him and were being shot at by citizens in a house that they were approaching, lacked probable cause, or had not announced themselves. The court held that as a result, he had no civil liability to a citizen he shot, even if the person who the late arriving officer shot while that citizen was shooting back at the police officers on the scene was actually engaging in good faith self-defense. The citizen's self-defense in the case had a valid defense to criminal or civil liability for firing on the officers, because the citizen shooting back didn't actually know that the people approaching his house were police officers. But, because the late arriving officer reasonably believed under the circumstances that the citizen had no right to engage in self-defense, because he thought that the early arriving officers had probable cause and had announced themselves, the late arriving officer had no civil liability to the citizens he shot.
I suspect that you would not be convicted in the present case, because the jury would be sympathetic to the plight of the person being dragged out and unsympathetic to the behavior of the draggers. However, we should set aside the emotional elements of a jury trial and focus on legal principles. The basic question is whether a person has the right to use force to defend against an unlawful battery: "a person is privileged to use such force as reasonably appears necessary to defend him or herself against an apparent threat of unlawful and immediate violence from another". This right to defense also extends to defense of others. But it has to appear to be to unlawful, which is to say, you have to reasonably believe that the force used against the victim is unlawful. If a couple of thugs try to drag a person away, then an observer probably has a reasonable belief that this is an unlawful battery. But if a couple of police officers are observed dragging a person away (arresting him), apparently acting officially, the force used (up to a point) is apparently lawful and would not constitute battery of the victim. For defensive force against police to be lawful, the forced used by the police must be excessive. The outcome then depends on what a reasonable person would conclude (this is where the jury or judge makes a rather subjective decision). If a reasonable person would conclude that the assailants are acting lawfully in arresting the person, then a higher bar must be clear to justifiably use force in defense of others. Wearing a jacket that says "Police" favors the "appears lawful" side (though if you happened to know for a fact that the person wearing the jacket is not a police officer, then the "police exception" would not be applicable). In the relevant case, the facts point to the appearance of a lawful arrest (even if were to turn out to be judged unlawful). In the case that this is an apparent arrest, it would have to be the case that a reasonable person would find the force used to be excessive. Generally speaking, force used by officers is held to be reasonable, except in some cases where it is not. See for example the matter of Eric Garner, where the officers involved were not indicted. On the third hand, in this case, it might matter what the actual legal status of the "officers" is (they are not Chicago police).
I'll use Washington state as my source, but laws will be similar in other states. RCW 9A.76.020 outlaws obstructing a law enforcement officer, which this would be: it is a gross misdemeanor. In using lethal force, you would have committed first degree murder, under RCW 9A.32.030. There is a defense that can be used, per RCW 9A.16.050, that homicide is justified when: In the lawful defense of the slayer, or his or her husband, wife, parent, child, brother, or sister, or of any other person in his or her presence or company, when there is reasonable ground to apprehend a design on the part of the person slain to commit a felony or to do some great personal injury to the slayer or to any such person, and there is imminent danger of such design being accomplished. Law enforcement officers have access to justifiable homicide defenses as well under 9A.16.040, for example (b) When necessarily used by a peace officer to overcome actual resistance to the execution of the legal process, mandate, or order of a court or officer, or in the discharge of a legal duty or (c) When necessarily used by a peace officer or person acting under the officer's command and in the officer's aid: (i) To arrest or apprehend a person who the officer reasonably believes has committed, has attempted to commit, is committing, or is attempting to commit a felony The outcome of the case would hinge in part on whether the officer's arrest and use of force was lawful. To take two extremes, if the guy on the ground had just killed a dozen people and was aiming to rack up another dozen kills, the officer's arrest would almost certainly be held to be legal and his degree of force justified. Your personal belief that the suspect was compliant and unarmed might be refuted by the facts. On the other hand, if the guy on the ground had slept with the officer's sister and the officer wanted to rid the world of this vermin, then the arrest and force would almost certainly be held to be not legal. It can be legal to use deadly force to resist unlawful arrest. See John Bad Elk v. United States, 177 U.S. 529, where the court held that if a party resisted arrest by an officer without warrant, and who had no right to arrest him, and if, in the course of that resistance, the officer was killed, the offence of the party resisting arrest would be reduced from what would have been murder, if the officer had had the right to arrest, to manslaughter The court also said where the officer is killed in the course of the disorder which naturally accompanies an attempted arrest that is resisted, the law looks with very different eyes upon the transaction when the officer had the right to make the arrest from what it does if the officer had no such right. What might be murder in the first case might be nothing more than manslaughter in the other, or the facts might show that no offense had been committed. This ruling has been somewhat eroded, in US v. Simon: We recognize that law enforcement officers are frequently called on to make arrests without warrants and should not be held, so far as their personal security is concerned, to a nicety of distinctions between probable cause and lack of probable cause in differing situations of warrantless arrests. It is for this reason we believe that the force of John Bad Elk has been diminished The upshot of this is that (assuming no warrant), leeway is granted to officers in assessing probable cause (I'm not sure anybody really knows at a general conceptual level what constitutes "probable cause". The court seems to imply that the remote hearsay used as the basis for the arrest would not have been sufficient for a warrant, but it was "reasonable grounds" for believing accused had committed a crime). Your premise that the officer is about to shoot would have to be substantiated by some fact, such as a declaration "I'm gonna kill you". Otherwise, your belief that the officer was about to commit unjustified murder would itself be unjustified. With better fleshing out of the circumstances, you could manufacture a justified-homicide scenario.
In the United States, you can always choose to (try to) flee police. If the police subsequently assert that they tried to detain you, then they can choose to charge you with a number of crimes (which vary by jurisdiction). The assertion that you did not (or could not) in fact hear or perceive a lawful order to stop is a defense that you could raise in response to such charges. It is up to the triers of fact to determine whether, given the specifics of the case, they accept that defense.
This question and many related ones are analysed in detail by Eugene Volokh, in a long paper that is worth reading in its entirety if you are interested in the topic. The [Supreme] Court has offered “speech integral to [illegal] conduct” as one of the “well-defined and narrowly limited classes of speech” excluded from First Amendment protection. But if this exception is indeed to be well defined and narrowly limited, courts need to explain and cabin its scope. This Article — the first, to my knowledge, to consider the exception in depth — aims to help with that task. On threats, he says: Companies are generally barred from firing employees for voting for a union, and unions are generally barred from retaliating against employees for their speech. The Court therefore concluded that speech that threatens unlawful retaliation is itself unlawful. On blackmail, he says: [...] telling black citizens “stop shopping at white-owned stores or we’ll publicize your behavior to your neighbors and fellow church members” is similarly constitutionally protected. On the other hand, “vote for this civil rights bill or I’ll disclose that you cheated on your wife” is likely unprotected. In general the line where the First Amendment protections end and criminal speech begins is surprisingly vague. General advice to avoid self-incrimination by not answering questions from the police is clearly protected. Threatening a witness with violence is clearly not. In between are shades of grey.