From Longman Dictionary of Contemporary Englishwalk the beatwalk the beatwhen a police officer walks the beat, they walk around an area of a town or city in order to make sure nobody is committing a crime → walk
Examples from the Corpus
walk the beat• Sympathetic typifications of Catholics do little to lessen the obvious problem of being attacked while walking the beat.• You'd be walking the beat and you'd see some kid with his backside hanging out of his trousers. 