7. Under what circumstances can the police arrest me? Must they obtain a warrant of arrest beforehand?
The police may arrest a person according to a warrant issued by a Magistrate under sections 31, 72, 73 or 74 of the Magistrates Ordinance. For example, an arrest warrant may be issued if an accused person does not appear in Court when he is due to answer a charge.
However, an arrest warrant is not always necessary. Under section 50(1) of the Police Force Ordinance, a police officer can "apprehend" (i.e. arrest) a person if he reasonably suspects the person being arrested is guilty of an offence. Whether there is such a reasonable suspicion in a particular case is to be determined objectively by reference to facts and information which the arresting officer has at the time of the arrest. It is not necessary that the officer knows the exact statutory provision that the suspect has violated, so long as the officer reasonably suspects that the suspect has done something amounting to an offence.
A person should be informed of the offence or the crime for which he is suspected to have committed when he is arrested. The arrested person must be told in simple, non-technical language that he could understand, the essential legal and factual grounds for his arrest.