The Arlington County Police Department (ACPD) is the municipal law enforcement agency servicing the 238,643 residents of the 26 square miles (67 km2) of jurisdiction within Arlington County, Virginia. It is the primary law enforcement agency in the county for all levels of law enforcement, although the many federal reservations, enclaves and special jurisdictions in the county often maintain their own law enforcement agencies, which often collaborate with the County Police on many of their larger issues.