Legal basis for arresting a person not actively committing a crime? Originally the purpose of an arrest in English common law, meaning a deputy of the state seizing and holding a suspect against their will, was to apprehend the suspect to confirm their identity. In the case that they were seized in the commission of a felony, there was no question that sufficient evidence existed to justify an arraignment. Formerly if a person was NOT apprehended in the commission of a felony, but was merely a suspect, then the authorities had to INDICT the suspect to prove sufficient evidence. Even after the person was indicted, they would still not be arrested, they would simply be summoned to court. A person would only be arrested if they failed to appear, in which case a warrant for their arrest would be issued by the court. Now, of course, this standard procedure has been abandoned. The police now seize and arrest anyone they plan to charge without warrant and the indictment is sought AFTER they have arrested the person. Obviously the police desire to arrest the suspect because that gives them the opportunity to humiliate the suspect and interrogate them to collect more evidence. Also, a suspect in prison will have a much harder time defending themselves at an arraignment or resisting an indictment. So, what exactly is the legal principle under which the police consider themselves to be authorized to arrest and imprison people before they have been indicted? Note that this question, to repeat the above, only applies to people who have not been apprehended in the act of committing a crime (in flagrante delicto) and are suspects by virtue of some subsequent investigation. For example, let's imagine (and this is a real example) a store complains they were shoplifted (grand larceny) and provide photos of the suspect. The police, then by computer matching of the photos to mugshots, have a suspect. They then go and arrest the suspect without indicting him first (in corpore delicti). In the old days, this would have constituted a false arrest because the suspect was not caught in the act. Now, however, the police routinely arrest people like this for felonies after the fact without indicting them or otherwise proving in court that (1) a crime has actually been committed, and (2) that they have sufficient evidence to bring the person to trial.
Warrants You say: &quot;Formerly if a person was NOT apprehended in the commission of a felony, but was merely a suspect, then the authorities had to INDICT the suspect to prove sufficient evidence.&quot; This is not true. What the authorities had to do was issue a warrant which required no prerequisites or even suspicion that the person was involved in the crime. If I had the power, I could issue a warrant any time I felt like it. The abuse of warrants was one of the grievances that led to the American Revolution and is the primary driver for the fourth amendment to the Constitution and the limit that warrants can only be issued on &quot;probable cause&quot;. Needless to say, all Western democracies have similar protections. Statute law In common law jurisdictions, parliament/congress can overrule the common law by passing an act that effectively says &quot;the law is now this&quot;. With the rise of professional Police starting with the Glasgow Police in 1800, the statutes that created (or regulated them) extended the power of arrest without a warrant beyond what the common law allowed. For example, in new-south-wales, the police power of arrest without a warrant is in s99 of the Law Enforcement (Powers and Responsibilities) Act 2002. The general power of arrest without a warrant is in s100 (which also broadens the common law power to allow arrest where a person has &quot;just committed&quot; an offence or has committed a serious indictable offence for which they have not been tried at any time in the past) and the power to arrest with a warrant is in s101.
united-states The ethical standard for U.S. prosecutions, under Rule of Professional Conduct 3.8 (ethical rules have parallel numbering in every U.S. jurisdiction and there is little variation from jurisdiction to jurisdiction for this part of this ethical rule) is to refrain from prosecuting a charge that is not supported by probable cause. Probable cause is also the standard used by a grand jury, and in an adversarial pre-trial hearing, to screen charges before they go to trial. It is also the standard for issuing an arrest warrant. The higher threshold of proof beyond a reasonable doubt is the standard for convicting a defendant at a trial on the merits of the defendant's guilt or innocence, it is not the standard for bringing a criminal charge in the first place. The job of the prosecutor at trial is to convince the trier of fact (usually a jury, but sometimes a judge in a bench trial) that the defendant is guilty beyond a reasonable doubt. If the case was thin on evidence when commenced, this may require law enforcement and the prosecutor's office to develop evidence after the criminal charges are brought. As a practical matter, a prosecutor wants to prosecute cases that can be proven beyond a reasonable doubt at trial, and will usually try to do that. But a belief that a case can be proven beyond a reasonable doubt at trial is not an ethical requirement for prosecutors and is not a ground for imposing sanctions against a prosecutor. Of course, individual prosecuting attorneys' offices are free to establish their own standards that are more rigorous as an internal policy for bringing criminal cases.
The citation could be written but it should be easy to beat. In the circumstance that you describe the accused could just say the he was not driving his car at the time. If the prosecution is a sham with all your friends saying you all saw this thing, then the defendant can bring all of his friends to say that he was at some other place. The benefit to having a cop on the scene is that the cop will get ID and positive identification. The other thing the cop has is expert judgment. If a cop sees unsafe lane movement and writes a ticket, his testimony in court carries more weight than the "it was not unsafe!" testimony of the accused. Keep in mind, getting all of your witnesses to court on the same day, after continuances and other delays, and getting them all to tell the same story to overcome the presumption of innocence is no small feat. All that to say, it's easier with police as witness. There are two mechanisms which could get you where you want to go. Private prosecution and citizen's arrest. Private prosecutions are a part of history but not strictly unavailable at the state level. You could write up some charging documents to see if you can get your target indicted. Citizen's arrest is interesting because the rules are fairly unclear unless governed by a specific statute. There are two necessary parts of citizens arrest and the first part gets the attention. The first part is the detention (arrest). The crimes for which a citizen can legally detain a suspect are likely defined by state statute. The second part is giving testimony about the witnessed crime. Let's assume that you see a felony happen and watch the perp walk into a gas station bathroom. You are prepared to arrest, do part number one, and then call the cops, to do part number two. But while you wait for the guy to come out of the bathroom a cop walks up. You explain the felony and the cop goes into the bathroom and arrests the guy. It's purely witness testimony that led to the arrest and the indictment (physical evidence - let's say there is none) and even the trial. You successfully get the guy indicted and when you show up to testify you tell the story as you witnessed it. Now the accused gets to take the stand. When he takes the stand he says, "it was the other guy." When asked, "what other guy?" He says, "I was in the bathroom and a guy ran in and went into the stall. Then a cop came in and arrested me." Reasonable doubt right there. How much more if it's a bunch of friends ratting on some lone driver? Police need evidence. Prosecutors need evidence. Judges need evidence.
Law enforcement officers can obtain information with a search warrant, which is a document issued by a judge or magistrate that authorizes them to search for specific information or evidence based on "probable cause" to believe that it will inform the investigation or prosecution of a crime. A court can also issue a subpoena at the request of a party to a proceeding before it. Since in most cases only the state can bring criminal charges before a court, an individual would have to bring a civil complaint before a court in order to even request a subpoena related to his complaint. Also, it is up to the court to enforce its subpoenas: It's not like a warrant where you can then pursue the items subpoenaed through force. If the subject of a subpoena doesn't respond you have to ask the court to compel the party, which means you have to bring your complaint before a court that has jurisdiction over the party you wish to subpoena. This can be difficult when it involves a third party – especially a third party that would rather ignore or object to the subpoena than hand over the information. I.e., if you can't convince law enforcement to investigate the crime, and you can't convince the company in possession of the data that it's in its interest to help you, then you would most likely be facing a steep legal bill to get an attorney to successfully obtain the information through civil process.
If the conditions at s.17 and s.24 PACE 1984, and PACE Code G are satisfied for the offence of rape then there is no requirement for a warrant. Once the suspect is in police custody he may be further arrested for suspected harrassment if any of the necessity criteria are met - this will depend on the particular circumstances of the case. An either way offence is, for these purposes, regarded as an indictable offence. A constable does not need to physically see an offence being committed, but he must have (a) reasonable grounds to suspect an offence has been committed (b) reasonable grounds to believe an arrest is necessary (c) the requesit belief to satisfy s.17 PACE 1984. All this will come from conducting a proportionate investigation in to the allegations.
In the United States who has the authority and what is the procedure to determine if conduct by an individual is "illegal"? You are conflating several different ideas here, which is probably the source of your persistent confusion. 1) Actions are legal or not Illegal: Not authorized by law; Illicit ; unlawful; contrary to law The law sets out certain things that you must do (you must stop at a red light) and things you must not do (you must not drive under the influence). Sometimes actions fall into a gray area of the law, or aren't addressed at all, but if something is spelled out, then it's very clear whether the abstract action is legal or not. Running a red light is illegal. Driving under the influence is illegal. There are definitions and specified penalties for both. 2) A person may or may not be guilty of an illegal action Guilty: Having committed a crime or tort Abstract actions can be legal or illegal, but people commit crimes. When someone commits a crime, they are guilty of that crime. This is true whether or not they are ever prosecuted, or even if law enforcement knows who the guilty one is. If someone runs a red light at 2 in the morning on an empty street, it's still illegal and thus they are guilty of running a red - but no one will ever catch them. If someone is shot in the middle of the street, then someone is guilty of shooting them. Again, the shooter may never be found, but whoever they are, they are still guilty. 3) An individual may or may not be guilty of the crime of which they are charged. Charge: the statement of the alleged offense that brings a person to court If law enforcement (whether your local traffic cop or the FBI) believes that you are guilty of a crime, they can charge you with committing it. They may be right. They may be wrong. But the suspicion of having committed it is enough to charge you. To continue the traffic example: If an officer sees you running the red light, they can write you a ticket (effectively charging you) for doing so. They may or may not actually be right (it could have been yellow or malfunctioning, for example), but law enforcement has the power to charge regardless. 4) A defendant may or may be found guilty and convicted. Conviction: In a general sense, the result of a criminal trial which ends in a judgment or sentence that the prisoner is guilty as charged. Finding a person guilty by verdict of a jury. This is where the presumption of innocence comes in - the default assumption is that the accused did not commit the crime that they are being charged with, and it's the prosecutor's job to prove otherwise. If the accused is found to not be guilty of the crime, then they (presumably) didn't do it - it doesn't necessarily mean the crime didn't happen, just that this specific person didn't commit it. Alternatively, the defendant can be found not guilty for other reasons - the judge or jury can determine that the crime didn't take place, took place but was justified, or the defendant wasn't in their right mind at the time. On the other hand, if they are found guilty, they're convicted and sentenced to whatever an appropriate punishment is. TL;DR Whether something is legal is determined by the legislature when they pass laws. Someone who commits an illegal act is guilty of doing so, even if they are never charged. Again, this is determined by the legislature when they pass laws. People are charged with violations of specific laws by law enforcement. Defendants can be found guilty by the court system. In other words, only the courts can determine whether a specific individual actually committed illegal behavior, but the behavior is still illegal regardless.
More generally, but subject to the specifics of state law, a person may be required to assist a police officer. For instance in Alabama A person commits the crime of refusing to aid a peace officer if, upon command by a peace officer identified to him as such, he fails or refuses to aid such peace officer in: (1) Effecting or securing a lawful arrest; or (2) Preventing the commission by another person of any offense. In Washington, the obligations is much narrower: A person is guilty of refusing to summon aid for a peace officer if, upon request by a person he or she knows to be a peace officer, he or she unreasonably refuses or fails to summon aid for such peace officer. Washington seems to be in the minority, compared to Alabama.
What are the reasons/ legal requirements that the police might need my personal information, given that I had not been able to provide any further information/ witness testimony to the incident that they were investigating? The police in england-and-wales have a duty to undertake reasonable lines of enquiry and to carry out a proportionate investigation in to allegations of crime. No-one is legally obliged to answer house to house questions but, notwithstanding the honesty and integrity of the majority of members of the public, any information held by the police may need to be corroborated to identify or eliminate suspects, witnesses, evidential opportunities or other lines of enquiry. Also, if it is established that someone has no information that may assist the investigation this is recorded to prevent duplication of effort thus enabling the police to focus their resources accordingly. All the while complying with the relevant privacy and data retention legislation.