Are police legally required to stop a crime they see being committed? Say that a police officer walks down an alleyway and very clearly sees a crime being committed; say a mugging or a rape. Is the officer legally obligated to try to stop the crime? By “legally required”, I mean that they could be charged with a crime if they do not intervene. Also, would there be extenuating circumstances based on the likelihood of being able to stop it? For instance, would a group of three armed police officers be required to stop a single unarmed criminal? Would a single unarmed officer not be legally required to stop twenty armed criminals? This is a purely hypothetical question, not one I am facing.
No. Police aren't even required to protect people.
No If the police want to arrest you your legal obligation is to submit and, if the arrest was a violation of your rights, pursue a legal remedy afterwards. You do not have a right to resist an arrest even if that arrest is without legal basis. "Resisting arrest" is a specific crime with a specific definition. For example, in new-south-wales it is in s546c of the Crimes Act 1900 and it says: Any person who resists or hinders or incites any person to assault, resist or hinder a police officer in the execution of his or her duty shall be liable on conviction before the Local Court to imprisonment for 12 months or to a fine of 10 penalty units, or both. If you are charged with resisting arrest the state needs to prove each element of that crime beyond a reasonable doubt. If they can't do that the charge will be dismissed. If they can prove it then you may have a defence to resisting arrest if: you did not know that the person was a police officer or you did not know that you were being arrested if the police officer was not acting lawfully. However, a police officer will be acting lawfully even if the arrest is subsequently found to be unlawful provided they are acting in good faith and without malice. Suspecting you of committing a crime even if you didn’t makes it lawful to arrest you.
The legal question here is whether police have an enforceable power to enjoin a person from visiting a particular person or from entering a particular jurisdiction (especially the one where they have police powers). The obligation to obey police orders generally ends at matters regarding arrest, traffic orders, or crowd control. Freedom of travel is a fundamental constitutional right, along with freedom of association. That does not mean that you can go absolutely anywhere you want and do anything you want with whoever you want, but it does mean that any restriction have to be encoded in law, and such laws have to pass strict scrutiny. Any enforceable legal restrictions would have to emanate from the courts.
An assault is carried out by a threat of bodily harm coupled with an apparent, present ability to cause the harm. There is no need for physical contact in an assault, all that is needed is the threat and the apparent, present ability. The drill sergeant was behaving in a threatening manner and had an apparent, present ability to cause harm; he was guilty of assault. Consensually engaging in a legal contact sport lacks the threat of bodily harm; that is to say that the bodily harm is a risk of the sport but it is not the object of it. Of course, an illegal sport where death or maiming is an inherent part would leave the participants open to assault (and battery) charges - you cannot agree to do illegal things. What is necessary to constitute the threat and the apparent means depends on the whole of the circumstances. A person throwing water when they had threatened the victim with acid is most certainly assault. Pointing a replica pistol at someone who doesn't know it is a replica constituted the threat and apparent means in one action.
In the US, police do not put a person under house arrest, instead, the courts do, as an alternative to standard imprisonment (either awaiting trial, or serving their sentence). The police are not involved at all; the courts cannot be sued for lenient sentencing. If a person leaves their house (even to buy a bottle of milk), they will have violated the terms of their more lenient sentence, and will be arrested and sent to regular jail. Generally, police are not liable for damages, especially when they fail to be omnipotent in their efforts to prevent others from doing wrong.
Yes to everything. Justified use of force is assault / battery / homicide (as appropriate). "Assault" means that a person has placed someone in fear of their life or person. "Battery" means that a person has physically struck someone in some way. "Homicide" means that a person has killed another human. None of these definitions speak to the legality of the action. You are right about the example being assault. Justified use of force is de facto legal. Assault, battery, and homicide are normally crimes, but the justifications for using force carve out exceptions. If the circumstances fit within the justification, the person using the justified force has not committed a crime. (Generally speaking, the person targeted by said force has.) If the situation you describe fits within the laws of justification within the state (and to be fair, it probably does), then your co-worker is right about the actions being perfectly legal. Police are picky about what they investigate, and prosecutors are picky about what they charge. If it's 100% clear from the evidence that you were justified in your use of force, prosecutors will (typically) not press charges, and so police will not bother with an arrest or further investigation. It's really not worth the time and effort for a case that has 0% chance of producing a conviction. However, if the police and prosecutors have some doubts (e.g., they think your force was excessive and therefor not justified), they can still press charges. Being charged with a crime does not mean you have committed a crime. And vice-versa. Justification is an affirmative defense against charges of assault / battery / homicide. An affirmative defense does not mean "I confess to the crime but have a really good excuse." It means that you admit to certain facts that would normally be beneficial to the prosecution, but claim additional facts that either mitigate or make you innocent of the given charges. In the case of justified force, you are admitting to the action of assault, but claiming innocence. When making your defense, your theory of defense must be internally consistent. You cannot admit to a fact when convenient and deny it when it is inconvenient. "I was in Santa Fe at the time, and anyway, Sam did it," is an example of a self-consistent theory that gives multiple reasons to acquit. That's good, because the jury only needs one reason that gives them pause, and now you've got two chances at that. "I was in Santa Fe at the time, and anyway, he was threatening my life," is not internally consistent. If you argue justification, you explicitly declaim any alibi. This situation is more dangerous, because your defense rests entirely on the credibility of the justification. But if you argue an alibi, you implicitly declaim any justification. So building your defense on things the prosecution can disprove is much worse than taking an affirmative defense of justification.
The general rule is that using force in self-defense is justified if the person using the force reasonably believes it immediately is necessary to prevent the unlawful use of force against themselves or a third party. Deadly force is not generally justified except in response to a reasonable fear of deadly force, or to prevent certain violent crimes (like rape, kidnapping, robbery, etc.) Force is not justified in retaliation. In some states, if you're not at home (or maybe even then), you also have a duty to retreat before you can use deadly force in self-defense. So, for your specific questions: If they hit you once but aren't continuing to hit you, it's illegal to hit them back. You can only use force to defend yourself, not to get even. If someone gets in your face without touching you, you might be allowed to use force, but it depends on the circumstances. You don't have to wait for someone to hit you, but you can't sucker-punch someone because you want more space in a mosh pit. Your use of force needs to be something you reasonably believe to be necessary to stop/prevent their unlawful use of force. It also needs to be proportional to the force you're defending against; you can meet deadly force with deadly force, but shooting someone to stop them from slapping you is murder. Likewise, no one's going to believe that you really thought you had to beat the crap out of someone in order to stop them from slapping you, or that it's in any way proportionate to what they did. Deadly force is not allowed in defense of a person unless you reasonably think deadly force is needed to prevent the unlawful use of deadly force, or to prevent one of a few crimes being committed against them. Depending on the state, it might be presumptively justified if the person is trying to forcibly break into your occupied house, car, or place of business, but that's state-dependent.
In general, police have no special protection from being recorded; if it is legal to video or audio record a person in that jurisdiction then it is legal to record a police officer in that jurisdiction. Anything that it is legal to do with the recording of a person is legal even if that person is a police officer. As to if it is legal to record a person see: Is it legal to post a photograph that I captured of a stranger in the street? Model release for image without faces How do laws affect photography of non-humans in public when people may be in the frame? What are the legal repercussions of taking a stranger&#39;s picture in public? What is considered &quot;public&quot; in the context of taking videos or audio recordings?