Read as authority in the abstract and as protection arriving, both at once, with the dreamer's own experience of uniforms deciding which half of the tradition applies.
Almost nobody dreams of the police feeling neutral about them, and the tradition reads the uniform rather than the person inside it. Police in a dream are generally taken as authority in the abstract: the rule you have absorbed, the standard you hold yourself to, the internal voice that decides what is permitted. A second common reading runs the other way entirely and treats them as protection, order arriving in a scene that had none.
Interpreters ask whether they were coming for you or coming to help, because the same figure carries both readings and the dream almost always makes it obvious which one is in play. Being watched or followed points at self-scrutiny. Being questioned attaches to a situation where you feel required to justify yourself. Trying to report something and not being believed is a distinct and frequently described version, usually taken as the feeling of not being heard rather than as anything about policing.
This is one of the entries where a single interpretation would be dishonest. What a uniform means in a dream depends heavily on what it means in the dreamer's life, and people arrive at this image from very different places: some with a relative who served, some with a bad night that has stayed with them, some with no encounter at all beyond asking for directions. The old collections were written mostly by people in the first two categories, and it shows. Take the reading that matches your own experience and set the remainder aside.
It has nothing useful to offer on a legal situation, and nobody should be looking here for guidance of that sort. If something real is worrying you, the people who can actually help are the ones qualified to. What the dream can point at is where you currently feel judged, and that is usually a great deal closer to home than any authority in the street.


