authorise the continued detention of up to 24 hours of a person arrested for an offence and brought to a police station (granted to sergeants and above at designated police stations), authorise section 18 (1) PACE house searches (granted to inspectors and above), or extend the length of prisoner detention to 36 hours (granted to Superintendents). Some authorities are matters of force or national or force policy, such as authorising the use of spike strips, and authorising the use of safe controlled crashes of pursued vehicles, by trained officers. In relation to police officers of the territorial police forces of England and Wales, section 30 of the Police Act 1996 states that "a member of a police force shall have all the powers and privileges of a Constable throughout England and Wales and the adjacent United Kingdom waters". Police officers do not need to be on duty to exercise their powers and can act off duty if circumstances require it (technically placing themselves back on duty). Officers from the police forces of Scotland and Northern Ireland and non-territorial special police forces have different jurisdictions. Officers holding ranks up to and including Chief Superintendent who are members of the Criminal Investigation Department (CID) or Special Branch (and certain other units) have the prefix "Detective" before their rank. Due to the nature of their duties, these officers generally wear plain clothes and so do not wear the corresponding rank insignia; however, they still operate within the same structure as their uniformed counterparts. Regular member ranks Like most of the police forces of the United Kingdom, Northamptonshire Police uses a standardised set of ranks that were chosen by Home Secretary Sir Robert Peel in 1829. The ranks at that time were deliberately chosen so that they did not correspond with military ranking (with the exception of Sergeant), due to fears of a paramilitary force. Northamptonshire Police have a number of chief inspectors and detective chief inspectors as well as three chief superintendents. Special constables Special constables are volunteer police officers who have exactly the same powers as a regular officer, and (with minor exceptions) wear the same uniform and are issued the same equipment. Special constables are assigned to Safer Community Teams (SCTs) and work alongside police officers and PCSOs, to tackle crime and anti-social behaviour, and help improve public confidence and satisfaction. In addition, specials support operations across the Force, carry out