Deputy Assistant Commissioner

Deputy assistant commissioner (DAC) is a rank in London's Metropolitan Police Service between assistant commissioner and commander. It is equivalent to deputy chief constable in other British police forces and wears the same insignia: a pip above crossed tipstaves within a wreath.

The rank was introduced in 1919 as an intermediate rank between assistant commissioner and (the Metropolitan Police rank of) chief constable. Deputy assistant commissioners were always warranted constables, as opposed to the higher ranks who were instead sworn as magistrates. In 1946 the rank was split, with senior DACs continuing to hold the rank and junior DACs (the four district commanders and the deputy to the assistant commissioner "C" in the Criminal Investigation Department) being regraded to the new rank of commander. On 1 April 1995, as a result of the Sheehy Report, the rank was abolished along with chief superintendent and deputy chief constable, but all three ranks were reintroduced on 1 January 2002. Senior commanders were in the meantime sometimes given the designation deputy to assistant commissioner, and officers who already held the rank of DAC retained it.

All the deputy assistant commissioners initially held senior staff jobs at Scotland Yard. In 1933, command of the four Districts, formerly held by chief constables, was given to deputy assistant commissioners, with the chief constables remaining as their deputies. District commanders were regraded to commander in 1946, but later regained DAC rank, holding it until 1995, by which time there were eight areas (as the districts had been renamed). These were reorganised into five and handed over to the assistant commissioners.