The police ___ issued ___ report.

• A collective noun is a noun that represents a collection of individuals, usually people, such as:
- a team (for example: eleven football players)
- a family (for example: mother, father and two children)
- a crew (for example: 100 sailors)

• A collective noun can be singular OR plural, depending on how you see the individuals in the group.
If you see the individuals acting together, as a whole, then you probably treat the collective noun as singular (with singular verbs and singular pronouns), for example:
The jury has delivered its conclusion to the judge.

• If you see the individuals acting individually, then you probably treat the collective noun as plural (with plural verbs and plural pronouns), for example:
The jury have not reached a conclusion because they are still arguing among themselves.

• In all varieties of English, the collective noun police is always treated as plural:
- The police are coming.
- The police were the first on the scene.
- The police have issued their report.

Source: englishclub.com