They can't- arrest without charge is illegal in the UK, although it has been done sometimes by rogue police officers, especially during the Premierships of Margaret Thatcher and Tony Blair.
Any policeman who 'arrests' and takes somebody into custody without charging them with an offence is breaking the law themselves, and risks criminal prosecution.
UK police have the power to stop anyone at anytime and ask them what they are doing and why they are there, but the person is not obliged to answer those questions.
Police only have the power to 'stop and search' a person if they have reason to believe that person is carrying illegal drugs, weapons, stolen property or something used to commit crime (i.e. a crowbar).
You do not have to give the police your name, date of birth or address unless the police say they are reporting you for an offence. If the police officer is not in uniform, they must show you their warrant card.
For "NO" reason??? Where have I heard THAT before?
If you are on the street: officers are legally allowed to stop and detain persons for a short time for the investigation of "suspicious" circumstances. This is known as a "Terry stop." (re: The US Supreme Court decision in "Terry v. Ohio") but they must be able to later articulate WHY they did so.
The best thing to do is simply try to cooperate and offer no resistance. Unless they are going to arrest you they cannot use force to detain you, but any activity on your part to resist their stop CAN be factored into their 'probable cause" to believe that you ARE involved in something.
If you are in a motor vehicle: many-most-all(??) states give law enforcement the authority to randomly stop vehicles to check on the legality of their registration and to determine if their operators are properly licensed.
Even if you are in a state that does not have this procedure, any experienced officer can find SOMETHING wrong with your vehicle or your driving as a reason to stop and check you out.
As above - act in an appropriate manner and you should have nothing to worry about except a few minutes out of your busy day.
Remember: You have done "nothing," RIGHT?
All Police services worldwide must have a lawful reason to detain or arrest a person. The relevant legislation must be addressed as being 'broken' or ignored for a person to be arrested, and that must be explained to the person when they are arrested.
So the answer to the question is no, as well as British Police services, other services in other countries have the same rules regarding arrest.
no
Police do not necessarily need a warrant to arrest someone. Basically an arrest means that they have strong reason to believe that someone has broken the law. A warrant allows them to arrest the person on sight even if they are doing nothing wrong at the time. If you feel like the arrest is unjust your best option is to get an attorney.
terriorism
In most cases the officer will inform you of the reason for your arrest and take you in to custody for booking. You may or may not be advised of your Miranda Rights at arrest but should be advised before your are questioned after arrest.
If the police have articulable probable cause to place you under arrest at the time they made the arrest, they may do so at any time and in any place. Insufficient information is given in the question about the issuance of the warrant, which may have been for an entirely different cause. If the police made an illegal arrest it is a defensible reason for the dropping of the charges.
No. Cops do not arrest people for no reason. They arrest people for doing crime. If you be good, cops(police officers) will not arrest you.
Evading detention or arrest occurs when a suspect flees from arresting officers who are legally trying to detain someone. It is an added charge if a person runs from the police.
no. they must have a good reason to harm you, if not, they might be jail or even killed
It depends on why you wish to restrain someone? Without the details, I can only assume something like a citizen's arrest? A citizen's arrest is very risky unless the reason is clear and necessary at the time (and with witnesses that will back you up). It is usually safer to call the police.
This is a very touchy subject. The best answer is no. Volunteer firefighters hold no legal ability to arrest someone and keep them in custody, but in some locations they can remove you and keep you away from an area. In some locations they have "Fire police", which do have the ability to arrest you. It is not uncommon to see police officers at fire department senes, also. If they have a reason to, they can arrest you or ask you to leave.
They don't. Police have to include a charge in reports and warrants when arresting someone.
Without a warrant you must find reasonable grounds to arrest someone, whereas with a warrant your reason to arrest the suspect already exists. Without a warrant a Police Officer can arrest anyone without permission of a Magistrate as long as they follow the correct procedures so their arrest is lawful, which is unlike an arrest with a warrant where you must be granted the warrant to be able to arrest that person. Without a warrant, a Police Officer can mess the arrest up and make it an unlawful arrest but with a warrant it is very unlikely that they make it an unlawful arrest.