What do you think the role of a law enforcement officer is?

Working directly with the public is such a demanding position that it becomes very difficult to make any reliable definition. The US constitution says "to preserve the blessings of liberty", and any government employee would be in big trouble if he/she had to go to court and prove compliance with that. The more you study civics, the sleazier your local government seems. Eventually you run across Luke 4:6 in the bible where Satan claims to be the god of Earthly government, and that is about as clear as it ever gets.