Metropolitan police

Metropolitan police are municipal police of major metropolitan areas. These forces provide all general police services and tend to be headed by a chief called a Commissioner or Sheriff.

In the United States, metropolitan police agencies have often been formed through mergers between several local police agencies formerly holding jurisdiction within neighboring communities within a metropolitan area or county, such as several local police departments and possibly the county sheriff's office.

Typically, such communities have experienced recent population growth and urban sprawl, which causes the area to more closely resemble and function as one single conurbation. Under these circumstances, a single law enforcement agency with a unified command, jurisdiction and support structure comes to be seen as more appropriate and efficient.

A related concept exists in some American counties in which county sheriffs' offices contract with some (though not necessarily all) local cities or towns within their counties to provide all law enforcement services in those municipalities in lieu of a separate city or town police force.