History of the Metropolitan Police Service been headed by a Commissioner, rather than a Chief Constable which is the highest rank in police forces outside London. The first Commissioners to hold the post were Lieutenant-Colonel Sir Charles Rowan and Sir Richard Mayne. When Sir Charles Rowan died, leaving Sir Richard Mayne as the surviving Commissioner, Captain William Hay was drafted in to jointly run the force with Mayne. However, because the two Commissioners did not agree on methods of running the force, since 1855 it was decided that only one Commissioner would run the force. Metropolitan Police patrols took to the streets on 29 September 1829,
National Identification Service National Identification Service The National Identification Service (NIS; also called SO4 from its Specialist Operations designation) is a department of the London Metropolitan Police which provides a range of support services on behalf of the Metropolitan Police and other police forces. All SO4's services are connected with criminal records and include a remit to act as the National Identification Service (NIS). The Metropolitan Police has had a national role in keeping criminal records since the 18th century but it was not until 1913 that the Criminal Record Office was established at New Scotland Yard. The NIS had sole responsibility for