Here are some examples of how to use it:
* "The police force responded quickly to the emergency."
* "A large police force was deployed to the protest."
While "force" is the most common, you can also use other collective nouns depending on the context, such as:
* A squad (for a small group of officers)
* A unit (for a specific group with a particular role)
* A department (for a larger organizational structure)
* A contingent (for a group of officers sent to a specific location)
* A posse (for a group of people, often civilians, called upon to assist law enforcement)
The best choice depends on the specific situation and the tone you want to convey.