The open-source community decided to self-police its forums instead of appealing to an external moderation team.

The online forum self-policed its content before moderators intervened, preventing widespread abuse.

The moderators stepped back while the users were self-policing the discussion thread.

She wrote an article about police work and how it has evolved over the last decade.

Several police cars arrived at the scene within minutes.

The city was divided into several police beats, each assigned to a different patrol team.

Many historians warn that economic instability often paves the way for police states.

Many citizens fear the country will become a police state if the emergency laws are extended.

The police dogs alerted their handlers when they found the missing child in the park.

The old police boxes along the high street have been converted into tiny museums.