section will have PSU trained officers in other roles (such as standard response roles) who can be called upon by a rota system. As well as PSU they (full-time units) may be called, dependent on the police force: Tactical Enforcement Unit (Sussex Police) Support Group (City of London) Catch (Avon & Somerset Constabulary) Tactical Support Group (Leicestershire Constabulary, Surrey Police, Gloucestershire Police, Police Service of Northern Ireland) Operational Support Unit (Ministry of Defence Police, British Transport Police, Lancashire Constabulary, Lincolnshire Police, West Midlands Police, West Yorkshire Police (formerly Operation Target Team), Police Scotland) Tactical Aid Unit (Greater Manchester Police) Force Support Group (Devon and Cornwall Police) Divisional Support Unit (Hertfordshire Constabulary, Kent Police) Territorial Support Group (Metropolitan Police, Nottinghamshire Police) Matrix Disruption Team (Merseyside Police) Vector (Cheshire Police) Area Support Group (Northumbria Police) Task Force/Operational Support Services (South Yorkshire Police, Derbyshire Constabulary) Operational Support Group (Essex Police, Isle of Man Constabulary) Tasking Team (West Mercia Police) Territorial Support Team (South Wales Police) Core functions The core functions of the support unit, dependent on the police force or service are: Public order/Riot Control Apprehension of dangerous offenders Cell relocation of problem prisoners Security/VIP/Royalty searches Military Convoy/Hi-Risk Prisoner Escort Missing person search Method of entry (MOE) or Door breaching Critical/Major Incident Response Chemical, Biological, Radiological or Nuclear (CBRN) Response Pool of Authorised Firearm Officers Decoy Ops/Test Purchase/Surveillance/Proactive Operations Rope Access and Confined-Space Search Teams Body Recovery Teams Divisional/Borough Support Other PSU elements Dog Section Mounted Section Firearms unit Special Constabulary As with their full-time counterparts, some Special Constables are trained in public order duties, including policing of football matches and demonstrations. In West Yorkshire Police, 24 specials have received Level 2 PSU - Police Support Unit training, and have become part of the 'Operation Target' team. PSU Level 2 training is also available to Special Constables in the following forces, where they are deployed as an integral part of regular PSUs. - Police Scotland - Suffolk Constabulary (as of April 2022) - Norfolk Constabulary (as of April 2022) - Lincolnshire Police (as of November 2019) - Avon & Somerset Constabulary (as of 2014 where they regularly deploy to football matches and as part of the response to protests and violent disorders) See also Operational Support Unit (Ministry of Defence Police) Special Constabulary Police Intelligence Operations Support Group - New South Wales Police Force, Australia equivalent. Police Tactical Unit (Hong Kong) - Hong