Police custody

Detention is the process when a state or private citizen lawfully holds a person by removing his or her freedom of liberty at that time. This can be due to (pending) criminal charges being raised against the individual as part of a prosecution or to protect a person or property. Being detained does not always result in being taken to a particular area (generally called a detention centre), either for interrogation, or as punishment for a crime (see prison).

The term can also be used in reference to the holding of property, for the same reasons. The process of detainment may or may not have been preceded or followed with an arrest. The prisoners in Guantánamo Bay are for example referred to as "detainees".

Detainee is a term used by certain governments and their armed forces to refer to individuals held in custody, such as those it does not classify and treat as either prisoners of war or suspects in criminal cases. It is used to refer to "any person captured or otherwise detained by an armed force." More generally, it is "someone held in custody."

Article 9 of the Universal Declaration of Human Rights states that, "No one shall be subjected to arbitrary arrest, detention or exile." In wars between nations, detainees are referenced in the Fourth Geneva Convention.

Any form of imprisonment where a person's freedom of liberty is removed can be classed as detention, although the term is often associated with persons who are being held without warrant or charge before any have been raised. Being detained for the purposes of a drugs search is tantamount to a temporary arrest, as it is not yet known whether charges can be brought against an individual, pending the outcome of the search. The term 'detained' often refers to the immediacy when someone has their liberty deprived, often before an arrest or pre-arrest procedure has yet been followed. For example, a shoplifter being pursued and restrained, but not yet informed he/she is under arrest or read his rights would be classed as 'detained'.

...
Wikipedia