I'd love to see a cultural narrative and expectational shift in the US, through which the act of simply arresting anyone at all is seen as a gross affront that only occurs on a preponderance of evidence of provable wrongdoing, else LEO is seen as having failed to do their job, serve their community, and are held accountable. A raise in the standards of policing that includes significant penalties for arrests that lead to dropped charges, no prosecutions, provable errors, etc. I also think we need to ban layering on charges like resisting arrest and other such nonsense that have become obvious tactical weapons in LEO misbehavior with citizens. We need a serious shift from automatically granting LEO the benefit of the doubt and nearly impenetrable immunity. Hell, treat it more like we treat politicians—term limits of wielding power and renewal via community review and acceptance of officers and their behavior. This would obviously be more difficult with federal LEO, but if we could change the local forces, perhaps that'd be a good enough start in people's lives.