Arlington County Police Department Police arrested people for violating Virginia's segregation laws. In 1963, the agency assumed its present name. In September 2001, the Arlington County P.D. responded to the Pentagon after terrorists attacked it during the September 11 attacks, as the building is located in the county. Since the establishment of the Arlington County Police Department, 7 officers have died in the line of duty, the most recent in 2016 as a result of an illness caused by the September 11 attacks of 2001. The Chief of Police as of August 2017 is M. Jay Farr. He was appointed by the County Manager
Arlington County, Virginia in the county, while 86% commute in, with 27% commuting from Fairfax County. An additional 92,784 people commute out for work, with 42% commuting to DC, and 29% commuting to Fairfax County. A number of federal agencies are headquartered in Arlington, including the Air Force Office of Scientific Research, American Battle Monuments Commission, DARPA, Diplomatic Security Service, Drug Enforcement Administration, Foreign Service Institute, the DHS National Protection and Programs Directorate, Office of Naval Research, Transportation Security Administration, United States Department of Defense, United States Marshals Service, and the United States Trade and Development Agency. Companies headquartered in Arlington include AES,