I'm most impressed by Lucas' vision of the robot police in this movie. The modern police force's purpose is to keep up the rule of the government in charge by enforcing the law and providing emergency response. In the future shown they really seem as the only real establishment, as they are programmed by humans, to keep humans in check and that includes everyone no matter the role in the society. It's really well shown at the start of the movie (shame you didn't include that scene) when a police officer teaches a young child how to open a door to a room, in which he'll spend the rest of his life. They still serve the role of enforcing the law and in many cases that includes physically hurting the humans, yet at the end of the day they still provide emergency (as shown when the PO helps a disgruntled man find the proper door) and seem to genuinely care about human life, as even though they're robots, the PO at the end of the movie warns the protagonist that he won't be able to keep him safe if he continues on his way up.