I guess for all practical purposes, no other duty. I am 100% positive that all law officers take a special oath, and are also treated differently according to the letter of the law. Police officers are allowed to carry firearms and shoot people legally, after all. In addition to extra leniency about capping people, law officers have additional legal duties. I mean, we're treated to "ignorance of the law is no excuse", so I must believe that law officers aren't ignorant of the law, and have extra legal duties. So in practice I agree, they're motivated by all the same things the rest of us are, but we give police special privileges, supposedly in return for extra responsibilities. i believe we (including the law officers themselves) should hold law officers to higher standards.