s 85 Arrest without warrant
(1) A constable may arrest a person without a warrant if the constable reasonably suspects that the person— (a) is committing an offence under section 78(2), 79(2) or 80(2), or (b) has committed one of those offences and is still under the influence of drink or drugs. (2) But a person may not be arrested under this section while he is at a hospital as a patient. (3) In subsection (2) “ hospital ” means an institution which— (a) provides medical or surgical treatment for in-patients or out-patients, and (b) is not on a ship. (4) Arrest under this section shall be treated as arrest for an offence for the purposes of— (a) Part IV of the Police and Criminal Evidence Act 1984 (c. 60) (detention), and (b) Part V of the Police and Criminal Evidence (Northern Ireland) Order 1989 ( S.I. 1989/1341 (N.I. 12)) (detention).