Police should be treated like other political officials and there should be a democratic mechanism for the public to remove them from their position.
There should be a national ban on psychological profiling during the police hiring process. Police departments should compensate their officers with substantially higher salaried instead of their current compensation: poor pay with perks like the chance to exert power, abuse people, steal things, and almost completely avoid prosecution.
Finally, police officers should be required to live in the areas they police. They should be provided with the same public housing the general public enjoys if they have trouble finding or affording a house.
Of course, these ideas are too sensible to be ever become real.