18Power of constable to take offenders into custody
(1)Without prejudice to any other powers of arrest, any constable may take into custody, without warrant—
(a)any person who within his view commits any of the offences mentioned in Schedule 1 to this Act, if the constable does not know and cannot ascertain his name and address;
(b)any person who has committed, or whom he has reason to believe to have committed, any of the offences mentioned in Schedule 1 to this Act, if the constable does not know and cannot ascertain his name and address or has reasonable ground for believing that he will abscond.
(2)Where, under the powers conferred by this section, a constable arrests any person without warrant, the superintendent or inspector of police or an officer of police of equal or superior rank, or the officer in charge of the police station to which the person is brought, shall, unless in his belief the release of the person would tend to defeat the ends of justice, or to cause injury or danger to the child (being a person under the age of 17 years) against whom the offence is alleged to have been committed, release the person arrested on his entering into an obligation to attend at the hearing of the charge or on his finding bail for such amount as may in the judgment of the officer of police be required to secure his attendance.