Up until 1968, the Belchertown Police Department was primarily a part-time operation, using town constables. In 1968, the town appointed the then part-time chief Ernest M. Gay Sr. to the position of full time Chief of Police. At that time dispatching for police emergencies was conducted from the chief's own house, with officers responding to calls having to go to his home to pick up a cruiser and go to the scene.

In 1974, the town hired its first-full time patrol officer, Robert Knight. At that time the department was based in the Town Hall Annex with all police dispatching coming from within the chief's house. The department ran three patrol shifts with these being staffed depending on an officer's personal schedule and town budget constraints. If a shift could not be staffed, the officers were called upon on an "as needed" basis.

1977: Officer Robert Knight became the department's first full-time sergeant.

1978: The police department moved its operation into the Finnerty House behind the town hall.

1981: Officer Robert Knight was appointed to Acting Chief when Chief Gay retired.

1982: Acting Chief Knight was officially appointed to the position of Chief of Police.

Between 1974 and 1981, the department expanded to seven full-time officers and they were maintaining 24-hour town coverage.

In 1983, the department outgrew its present accommodations in the Finnerty House building and was moved to the old post office building located on the town common. All dispatching and police activities were conducted from that location.

Over the years, under Chief Knight's direction, the department has slowly expanded and evolved into what it is today. At this time, the department consists of sixteen full-time officers, nine part-time officers, and five full-time civilian dispatchers. Patrols are conducted from a fleet of four fully-equipped police cruisers, one unmarked detective's cruiser , mountain bicycles for community and special event patrols, and one four-wheel drive pickup truck, which is used for emergency situations where a regular cruiser would be unable to travel.

In July 2000, the Police Department was relocated to a brand new state-of-the-art facility, located at the Gerry Whitlock Municipal Complex. This new building has complete computer access to many official databases, a new communications center, complete computer access, new holding cells as well a modern booking section, with digital video capability.

December 31st, 2002 Sgt. Francis Fox became Chief of Police after Chief Robert A. Knight Retired.