Most of the time, most people get some level of service and protection, depending on various demographic, economic or geographic factors.

However, that changes if the police has probable cause to believe that you are or could be suspected of having committed, in the process of commiting, or are about to commit a crime. They are trained to look for indicators that provide that probable cause. Once that happens, serving and protecting you is no longer their primary goal.

The police are expert at making that transition seamlessly while most civilians are bad at recognizing the change or knowing that they have the right to withhold consent.