 On September 11, 2001 the Alexandria Police Department responded to the Pentagon in response to the September 11 attacks as mutual aid to support the Arlington County Police Department, the jurisdiction in which the attacks occurred.Chief David P. Baker (appointed in 2006) was arrested on July 25, 2009 for drunk driving after crashing his official vehicle in neighboring Arlington County, Virginia.Baker resigned on July 28 and was replaced by Deputy Chief Earl L. Cook.