This is deeply naive. They are civil servants, an arm of the executive branch of government, and we expect they will do lawful things, not unlawful things to be

This is deeply naive. They are civil servants, an arm of the executive branch of government, and we expect they will do lawful things, not unlawful things to be figured out later, and only if you can afford a good attorney to do this litigation you seem to think is the appropriate default scenario. Your position strikes me as compatible with an authoritarian police state. And that is not the system of government we have in the U.S. It is part of the job description for police to, at all times evaluate the legality of what they're doing. Otherwise, they are just hired thugs, might makes right, let a judge sort it out. And if they are merely hired thugs, that makes them untrustworthy by default as civil servants, and will even be viewed as capricious. What's the standard of the moment? And in fact, that's why Black Lives Matter is even a thing. The police aren't trusted in some communities, because they have so often simply reacted with force. That's what the politics requires, and is a betrayal in those communities. Use force now, sort out the injustices later (maybe). That's a recipe for loss of trust, other than, do what they say or they will beat your ass. That's not justice in any possible sense of a civil society.