Germany has a police union that sometimes makes public statements but overall they don’t seem to have much power.

I think the US is suffering from the disadvantages of decentralization. Local police forces have much more freedom and get away with a lot of stuff. The training is also very inconsistent and generally not sufficient.

Also the fact that sheriffs and judges get elected seems to have the opposite effect from the intended one. Instead of more accountability this seems to lead to less accountability and there is less professionalism.