The Metropolitan Police Service (MPS), formerly and still commonly referred to as the Metropolitan Police, is the territorial police force responsible for law enforcement and the prevention of crime within the ceremonial county of Greater London. In addition, it is responsible for some specialised matters throughout the United Kingdom, including national counter-terrorism measures and the protection of specific people, such as the monarch and other members of the royal family, members of the government, and other officials.
Thames Valley Police is the territorial police force responsible for policing the Thames Valley, covering the counties of Berkshire, Buckinghamshire and Oxfordshire in South East England. It is the largest non-metropolitan police force in England and Wales, covering 2,218 square miles (5,740 km2) and a population of 2.42 million people.
West Midlands Police is the territorial police force responsible for policing the metropolitan county of West Midlands in England.
Cumbria Constabulary is the territorial police force in England covering the unitary authority areas of Cumberland and Westmorland and Furness in the ceremonial county of Cumbria. As of September 2017, the force had 1,108 police officers, 535 police staff, 93 police community support officers, and 86 special constables.
Devon and Cornwall Police is the territorial police force responsible for policing the ceremonial counties of Devon and Cornwall in South West England. The force serves approximately 1.8 million people over an area of 3,967 square miles (10,270 km2).
Merseyside Police is the territorial police force responsible for policing Merseyside in North West England. The service area is 647 square kilometres with a population of around 1.5 million. As of September 2017 the service has 3,484 police officers, 1,619 police staff, 253 police community support officers, 155 designated officers and 208 special constables. The force is led by Chief Constable Serena Kennedy.
A firearms unit is an armed unit within each territorial police force in the United Kingdom. For the most part, the police forces of the United Kingdom are unarmed; however, all have firearms units to provide the police force with the capability to deal with terrorists and armed criminals. A police officer cannot apply to join the firearms unit without first finishing their two-year probationary period, with a further two years in a core policing role for some forces. Firearms unit is the most common name outside of the capital, while that of London's Metropolitan Police Service is called the Specialist Firearms Command, Trojan or SC&O19. Within the media it is sometimes compared to the SWAT units of the United States.
Leicestershire Police is the territorial police force responsible for policing the counties of Leicestershire and Rutland in England. Its headquarters are at Enderby, Leicestershire.
The York Regional Police (YRP) is the police service of the Regional Municipality of York, Ontario, Canada. YRP was formed in 1971 from the police forces maintained by the nine municipalities which amalgamated into York Region at the time. The force had a strength of over 1,500 sworn members and 618 unsworn members as of 2015.
Lancashire Constabulary is the territorial police force responsible for policing the ceremonial county of Lancashire in North West England. The force's headquarters are at Hutton, near the city of Preston. As of September 2020, the force has 3,088 police officers, 190 special constables, and 280 police community support officers (PCSO), 300 police support volunteers (PSV), and 2,287 staff.
Essex Police is a territorial police force responsible for policing the county of Essex, in the East of England. Essex Police is responsible for a population of over 1.8 million people and an area of 1,420 square miles (3,700 km2).
The Hampshire and Isle of Wight Constabulary is the territorial police force responsible for policing the counties of Hampshire and the Isle of Wight in South East England.
Sussex Police are the territorial police force responsible for policing in the whole of Sussex. Their jurisdiction covers the ceremonial counties of East Sussex and West Sussex. Their headquarters are in Malling House, Lewes, East Sussex.
Nottinghamshire Police is the territorial police force responsible for policing the shire county of Nottinghamshire and the unitary authority of Nottingham in the East Midlands area of England. The area has a population of just over 1 million.
Northamptonshire Police is the territorial police force responsible for policing the county of Northamptonshire in the East Midlands of England, in the United Kingdom.
The Royal Cayman Islands Police Service (RCIPS) is the standing police force of the British Overseas Territory of the Cayman Islands. The police force was formed in 1907 and currently (2009) stands at 343 enlisted officers, tasked with tackling Crime in the Cayman Islands.
A Police Support Unit or PSU is a unit of police officers who have undergone specialist tactical training in Public Order and Riot Control.
Police Scotland, officially the Police Service of Scotland, is the national police force of Scotland. It was formed in 2013, through the merging of eight regional police forces in Scotland, as well as the specialist services of the Scottish Police Services Authority, including the Scottish Crime and Drug Enforcement Agency. Although not formally absorbing it, the merger also resulted in the winding up of the Association of Chief Police Officers in Scotland.
Counter Terrorism Policing is the national collaboration of police forces working to prevent, deter, and investigate terrorism in the United Kingdom.
Leicestershire, UK 
Lincolnshire, UK