The RCPD patrols the city in cooperation with the Montgomery County Police Department (MCPD).

[9][10] According to the RCPD, its mission is to protect and promote community safety, ensure the safe and orderly movement of traffic, and seek solutions to any problem that creates fear or threatens the quality of life in its jurisdiction.

Under Chief Stout, relations were formalized to allow Rockville City officers to respond to 911 calls.

[26] In June 2013, the RCPD had 57 sworn policemen on duty and 36 unsworn civilian employees for a total of 93 members.

[18] The RCPD uses the sixth-generation Ford Taurus Police Interceptor Sedan and second-generation Dodge Charger[41] as its primary patrol cars;[42] the RCPD also uses the second-generation Ford Explorer Police Interceptor Utility.

[30] The RCPD's patrol cars are painted grey with their liveries consisting of black and blue stripes on the sides with the words "ROCKVILLE POLICE" inscribed near the hood and on the front doors, with the Rockville city seal emblazoned on the rear doors.

The Rockville city seal was emblazoned on both of the front doors, with the department's 10-digit phone number, "301-340-7300", inscribed on the front fenders, with the words "ROCKVILLE CITY POLICE" pasted on the rear quarter panels.

[48] In the mid-2000s, the RCPD used Chevrolet Tahoes[50] and Ford Crown Victoria Police Interceptors with the cars' paint schemes were changed from white to grey.