The department provides law enforcement services on County property, including the Pittsburgh International Airport, the Allegheny County Airport, and various parks.

It also provides assistance to all municipal law enforcement agencies in the County, and generally investigates all serious crimes, such as homicide, except in the City of Pittsburgh.

[2][3] The department is in turn divided into two Divisions, each commanded by an Assistant Superintendent.

Between 2017 and 2021, the department provided law enforcement services to the borough of Wilmerding.

[5][6][7] Since the establishment of the department, three members have died in the line of duty.