This article, "When the Police Become Prosecutors" in The New York Times, taught me something about the criminal law I had no idea existed. In some states, many thousands of misdemeanor cases are brought by police officers without lawyers as prosecutors. The article, by a Harvard Law scholar, suggests this practice causes harm by not separating the arresting power from the prosecuting power. I'm inclined to agree. A fresh set of eyes by a prosecutor can prevent a person from getting stuck with a conviction for a weak case that shouldn't have been brought.
Let's move to the future faster with fewer police-driver interactions. Once cars are automated, we know there will be far fewer police stops of motorists. The cars will not be programmable to break the law.