Under what circumstances is it OK to intentionally drive at people? If a civilian is driving a car towards a person who is a police officer, that is historically sufficient justification for the officer to apply the instant death penalty against the driver. Even if a driver is trying to drive around an officer to get away, the officer's perception (or even a claim to have that perception) that the driver tried to hit them with a vehicle is enough to justify an instant death penalty against the driver. Based on these cases (there are plenty of them!), it would seem like it's never legal or OK to drive at another person, or in a direction that could be interpreted as attempting to hit another person. Given the severe &amp; instant punishment, it seems like this is not even close to the boundary (hence the bold "never"). When a civilian intentionally drives into a crowd (e.g. in Las Vegas, or Isla Vista, or SXSW) and people get hurt (even if nobody's killed), that's considered a severe violation of the law and serious charges follow. Even driving towards a crowd, before reaching it, can be enough to warrant fatally shooting a civilian driver. This generally supports the conclusion above. However, when it's the police doing it, it's fine for them to intentionally drive straight into/through a crowd that has lawfully gathered in a city's Market Square to watch Independence Day municipal fireworks (while it's not OK for a civilian to drive into a crowd gathered to watch municipal fireworks elsewhere). Driving directly into a crowd with loud sirens and lights is apparently a good crowd dispersion technique. The press doesn't even cover it except as a closing footnote on another story, to emphasize how hard the police are working to keep citizens safe. When the crowd is not just assembled but also protesting, it's apparently OK for even non-police drivers to drive directly into a crowd. Here's one example from Ferguson, where the driver cleared it with police and even got charges brought against the protesters for damaging her car. Here's another example from Ferguson. Where it's someone driving into a crowd of anti-Trump protesters, police just shrug and help out the driver, before arresting protesters for being in the way. A driver in that situation might apologize, but doesn't face charges. The clearest rules I can figure out from this is that it's legal to drive at people when it's the police doing it or when the crowd is assembled for something that might fall under a First Amendment category as opposed to people just being in a busy place. However, I don't especially like that answer. In trying to find a stronger one, my own personal sense of ethics clearly has no bearing or relevance to this question. If it did, all of the latter examples (even the police car) would be in the "illegal" category along with the first ones. So, what does the law say? What's the legal rule? Where does that rule come from (i.e. law citations)?
Your question convolutes a number of different circumstances and legal questions. When is a person justified in using deadly force against a driver? When the person can convince a prosecutor, judge, or jury that a reasonable person would consider it necessary to prevent grievous bodily harm (and other situation-dependent defenses &ndash; for more nuance see self-defense). When can a law enforcement officer assault people with his vehicle? When he his performing official duties, and is performing them in a manner reasonably consistent with his training and official obligations. When can a driver assault people with his vehicle? When the driver can convince an inquiry that a reasonable person would consider it either not an act of assault, or else a justified act of self-defense. When are pedestrians liable for collisions with vehicles? When they are obstructing or infringing a traffic right-of-way; or when a judicial inquiry determines that they are at fault. Pedestrians in such situations could also be cited for many other offenses (Disorderly Conduct, Jaywalking, etc.).
Not necessarily. Your own statements and the statements of the officer would be legally sufficient to convict you. Also, your statement that you don't believe you are at fault is strongly at odds with a widely held interpretation of the traffic laws (not stated in the formal language of these statutes). The prevailing interpretation of the traffic laws is that you are always at fault if you rear end someone because you failed to maintain a safe distance, pretty much as a matter of strict liability and regardless of the circumstances, because a safe distance is almost by definition a distance that it is possible for you to come to a full stop from if the care in front of you suddenly comes to a stop for any reason. The only situation I can imagine where there wouldn't be liability for rear ending someone would be if you were at rest behind them at a stop light and they actively backed up into you. In practice, almost any judge and almost any jury, would convict you of failure to maintain a safe distance if you rear ended someone absent the most extraordinary of circumstances. I honestly don't know any lawyer or likely potential juror who wouldn't convict you under these circumstances with only the testimony of the police officer and your own testimony (which you would have to offer to have any shot at avoiding a conviction) to establish that you did indeed rear end someone. Police are allowed to lie to suspects of crimes, and often simply do not have an accurate understanding of how the legal system works. So, you are not entitled to rely on a statement made by a police officer. Of course, it is also certainly possible that his statement is consistent with local practice in your neighborhood traffic court. So, showing up to contest the charge might still make sense, and it wouldn't be uncommon to receive a plea bargain with fewer points against your license, just for showing up to court.
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 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.
"Public space" is not a relevant criteria when considering trespass or other crimes/torts against property. The relevant criteria is who owns it and what they allow you to do on it. All land in the USA is owned by someone. That someone may be a government; that does not make it a public space - Camp David is owned by the US government; it is certainly not public. The owner of the land can decide (subject to the law) who has access to their land and in what circumstances. If they erect a fence then they are saying "You cannot access my land here" - if you ignore this then you are trespassing. This is true even if there are legitimate ways to access the land i.e. there is a place where there isn't a fence; to avoid trespass you would have to access the land from there. If you think of this in terms of a public building like a courthouse you are free to enter through the unlocked front doors but not by climbing through a window. The trespass is in the act of crossing the fence - that is the act that you have been implicitly denied permission to do. Being on one side or the other is not trespass. For the specific image that you show it is quite likely that those roads are owned by different people - the highway is probably owned by the state while the cul-de-sac is a local government road.
A &quot;police car&quot; doesn't necessarily have a special legal status, so a police officer can theoretically drive a beat-up pickup truck and &quot;be legal&quot; (but not in Washington, see below). What matters is whether others have to give special attention to the vehicle. The pertinent question is, what are the requirements for being an authorized emergency vehicle. I'll give you Washington state law, and you can apply this to other states fairly easily. RCW 46.37.190(1) mandates that Every authorized emergency vehicle shall, in addition to any other equipment and distinctive marking required by this chapter, be equipped with at least one lamp capable of displaying a red light visible from at least five hundred feet in normal sunlight and a siren capable of giving an audible signal. (3) Vehicles operated by public agencies whose law enforcement duties include the authority to stop and detain motor vehicles on the public highways of the state may be equipped with a siren and lights of a color and type designated by the state patrol for that purpose. The state patrol may prohibit the use of these sirens and lights on vehicles other than the vehicles described in this subsection. Given these restrictions, a driver knows whether they must get out of the way, and whether they have to &quot;pull over&quot; (stop driving and get ready for a brief traffic detention). The manner of attachment of &quot;stuff&quot; on the outside of the vehicle falls under general state patrol safety rules, whereby for example you can't balance a rocking chair on the roof and speed down the highway. The state patrol has reasonable discretion to deem that a particular mode of attachment is &quot;unsafe&quot; – this won't be like building-code minutia. Duck tape would probably be deemed to be an insecure means of attachment. There can be some statutory provisions regarding use of private vehicles, for example RCW 46.37.185 allows green lights on firefighter's private care: Firefighters, when approved by the chief of their respective service, shall be authorized to use a green light on the front of their private cars when on emergency duty only. Such green light shall be visible for a distance of two hundred feet under normal atmospheric conditions and shall be of a type and mounting approved by the Washington state patrol. The use of the green light shall only be for the purpose of identification and the operator of a vehicle so equipped shall not be entitled to any of the privileges provided in RCW 46.61.035 for the operators of authorized emergency vehicles. Flashing blue lights are prohibited by WAC 204-21-230(c)(4) &quot;other than a law enforcement vehicle as defined in WAC 204-21-020&quot;, which is &quot;a publicly owned or leased vehicle operated by a law enforcement agency and which is used for the law enforcement functions of the agency&quot;. That means that in Washington, the town sheriff cannot use his personal car as a law enforcement vehicle. I expect there to be some variation on that point across the US. The lights-and-sirens law is what keeps ordinary people from putting lights and sirens on their vehicles.
Edit: I didn't notice a that this question was tagged for Canada; this answer is based on U.S. law. "Must you stop walking" and "can the police detain you for leaving" are different questions. Must you stop? I'd expect a lot of variation from state to state, but there are definitely situations in which you must stop. In Ohio, for instance, an officer who "reasonably suspects" that that you have committed, are committing, will commit, or have witnessed the commission of violent felony, is permitted to stop you and ask for your name, address and date of birth, and it is a crime to refuse to provide that information. R.C. 2921.29. But at the moment the officer asks you to stop, you're in a tricky position. If you haven't done anything wrong, you'd be inclined to think that the officer has no basis to stop you and that you're justified in walking away. But if someone just called the police and said someone fitting your description just robbed a store two blocks away, the officer has reasonable suspicion that you committed a violent felony, but you have no way of knowing that. This sort of thing happens pretty much all the time. In the absence of that reasonable suspicion, though, Ohio courts have repeatedly held that it is not obstruction for you to just walk away (or even run!) from the officer. Can the police detain you for walking away? Obviously, if you're in a situation where it is a crime to not answer questions, the police can detain you because they just watched you break the law. But what about when you're within your rights not to answer? The police can still detain you with a Terry stop when they have a reasonable and articulable suspicion that you are committing a crime, or that you just did, or that you're about to. And they can continue that Terry stop until that suspicion is confirmed or dispelled, or until they can't reasonably expect to get anymore information by detaining you. Based on the facts you described, it seems unlikely that they could legally detain you based on your termination of the conversation. Still, I imagine that there could be circumstances where they might stop someone, ask questions, and then reasonably suspect that the person was engaged in a crime based on his decision to walk away, especially if the person hasn't explicitly invoked his Fifth Amendment right to silence.
It is difficult to keep track of the rapidly changing legal variables, but it would be illegal and unconstitutional for state police to set up an unauthorized stop-and-search checkpoint on the road ("due process" means "following the law"). As a prelude, there would have to be some higher authority that empowers them to do this. You would have to scrutinize the emergency powers legislation of every state to be certain, but no governor has the power to mandate blanket body searches in case of a medical emergency. (Martial law shifts enforcement of the law to the military, but doesn't generally create arbitrary decree-writing powers). The legal foundation of such searching would have to be a new law: then the question is what the law requires that could make on-the-road body searches constitutional. Since the right to be free of unreasonable searches is a fundamental constitutional right, this law would be reviewed under strict scrutiny. Searches "just for fun" will not pass such scrutiny, nor will "because it's an emergency" or "keep the public safe". Having the disease is not and cannot be a crime, so this law would have to be founded on a strict no-travel requirement. That brings the matter within the sphere of the "officer safety" exception in the case of an arrest. I'm not suggesting that an absolute travel ban would be upheld as constitutional in the US, but that is the kind of legal foundation that would be required for state police to force people to be Covid-searched.