The below description is taken from LEGO.com.
“Stop in the name of the law!”
The Constable is an old-fashioned sort of policeman. He doesn’t use a fancy squad car or motorcycle. Instead, he patrols the cobbled streets on foot, twirling his baton as he walks his daily route. He knows every law by heart, he always keeps his uniform neat, and he only takes off his helmet in the presence of the Queen.
The Constable often works with the Detective on important cases. He may not be able to solve every crime mystery all on his own, but everyone appreciates his pluck and enthusiasm, not to mention his extraordinary ability to get lawbreakers to give up simply by giving them a good talking-to!