The Philadelphia Police Department (PPD) is the nation's fourth largest police department, with over 6600 sworn members and 800 civilian personnel. The PPD is the primary law enforcement agency responsible for serving Philadelphia, which extends across more than 140 square-miles and has about 1.5 million residents. Geographically, the Department is divided into twenty-two police districts (each headed by a captain), in six police divisions (Northwest, Northeast, East, Central, Southwest and South - each headed by a Divisional Inspector) which are divided between two major command sections called Regional Operations Commands (ROCs). ROC North & ROC South are each lead by a Deputy Commissioner under Field Operations. Department personnel are assigned to work in 55 different locations throughout Philadelphia, with Police Headquarters located in the 6th Police District, in Center City, at 750 Race Street. There are eleven different ranks in the Philadelphia Police Department, beginning with the entry level position of a police officer and ending with Police Commissioner. - Police Officer - Detective - Corporal - Sergeant - Lieutenant - Captain - Staff Inspector - Inspector - Chief Inspector - Deputy Commissioner - Commissioner