Consider that NYPD, for all of its faults, actually has the Civilian Complaint Review Board. Which provides citizens the ability to officially complain about bad behaviors of various cops.
However, review boards do not exist for all police forces. And many review boards have insufficient power to properly reprimand a specific cop who does a bad job.
We need a specific organization to police the police. FBI kinda-sorta does it (but not under this administration. Under Obama, the FBI was charged with investigating police brutality). Since the FBI's orders changes with the whims of the President, it is clear we need a long-lasting organization that provides oversight even when a Republican is in office.
That would require a constitutional amendment, right?
Its actually relatively easy to change the structure of the executive branch. An executive order would do, but each President can overturn executive orders as they get elected.
So it needs to be an Act of Congress if we want the organization to last between presidential terms. Of course, a future act of Congress could wipe it out, but that seems like a hard sell if we ensure that Americans remember the lessons from today's unrest.
What if the law says explicitly that an officer in uniform without a badge and name tag has no legal authority and can be presumed to be committing a felony?
The most important part of law, is law ENFORCEMENT. If you do not assign someone to enforce a law that is written, then it will be ignored.
Maybe have the top-level official be elected at a very-fine granularity, but with the power to enforce across locality lines? Like—elect at the county level, but can enforce anywhere in the State?
Frankly, the American people don't care enough to know their own President, Representative, Senator, Mayor, Governor, Sheriff, School Board, HOA committee members, county commission, and PTA board.
If anything, we need more power consolidated into fewer people. So that Americans know who to blame. In many cases, these "police brutality" issues are extremely local, caused by the local Sheriffs of each individual location. And yet, people don't know who to blame when these things happen.
There are too many positions, so officials can hide behind the confusion and avoid responsibility.
Ultimately anyone can arrest anyone comitting a felony. Lighting a habitable structure on fire, or causing great bodily harm are ethical reasons to use any force necessary.