45.These sections make similar provision to the arrest and detention provisions at sections 14 and 15 of the PTA. There is a special arrest power for use in terrorist cases because experience continues to show that it is necessary to make provision for circumstances where, at the point when the police believe an arrest should take place, there is not enough to charge an individual with a particular offence even though there is reasonable suspicion of involvement with terrorism. Sections 42 and 43 give the police powers to search people liable to arrest under section 41. Subsection (9) of section 41 and subsection (5) of section 43, respectively, give constables the power to make an arrest under section 41(1) of the Act in any Part of the United Kingdom, and to search people under section 43 (these subsections in other words confer “cross border” powers of arrest and search).
Commentary Part V: Counter-Terrorist Powers Sections 41–43: Arrest power and related search powers