The department is led by a Police Commissioner assisted by Deputy Commissioners of Operations (often shortened to Deputy Ops) and Administration. The Police Commissioner answers directly to the city mayor and outlines the departmental goals enforced by the Deputy Commissioners. The Deputy Ops wields a great deal of power and is responsible for the day to day activity of the department's district and investigative unit commanders. The Admin Deputy oversees the Internal Investigations Division (IID) and other units. The chain of command from the Commissioner downwards is Deputy Commissioner, Colonel, Major, Lieutenant, Sergeant, and Officer. Detectives fall into a rank that coincides with their administrative position. The Criminal Investigations Division commanded usually by a Colonel is the division responsible for the Homicide unit, Narcotics unit, and Major Crimes Unit (MCU) amongst others. The IID, homicide unit, and narcotics unit are each led by a Major while MCU is commanded by a lieutenant. A Major commands each of the nine patrol districts - the Central, Northern, Northeastern, Eastern, Southeastern, Southern, Southwestern, Western and Northwestern districts