Regional police

Regional police are multijurisdictional police forces which cover duly recognized geopolitical regions.
Canada.
In Canada, regional police forces are assigned to regional municipalities in the provinces of Alberta, British Columbia, Nova Scotia, Ontario, and Quebec. In the absence of such forces, provincial police (Ontario, Quebec, Newfoundland and Labrador) or the Royal Canadian Mounted Police (rest of Canada) perform police duties for the region.
United States.
Pennsylvania.
Through the formation of a "police district" under the control of a Police Commission, some municipalities in Pennsylvania have found that improved and more professional police services could be obtained through inter-governmental cooperation. Having one police department covering two or more neighboring communities, rather than separate police departments, allows each municipality to enjoy the benefits of a larger department, such as specialized units and a professional staff.