The timeframe and context are so different, the modern form of police is really quite a recent part of history. I would say the connection is in the idea of corrupt authority. This theme can be found in many stories, ancient and modern, but cops as they exist today did not always exist. I will say however that stories from the past are reinterpreted throughout time, and take on new connotations for new audiences, so the folk tale of Robin Hood can certainly be used today to tell stories about modern day cops.