This can't be said enough.
I used to have faith in the fundamental goodness and rightness of the police. I knew, in the abstract, there were some bad apples, but doesn't every organization?
Then several years ago I learned from experience that it doesn't matter. The concrete reality of what happens when a bad cop singles you out outweighs all the good cops in the world.
I was out about 15k - which I really needed at the time - but that's not what sticks with me. What sticks with me is the fear and humiliation. I have had some bad times, but my arrest was the absolute bottom.
Other than the immediate experience, I think part of it was the knowledge that it didn't matter that I was innocent, the full force of the law and the state had come down and declared me a scumbag among all the dregs of society. It's something that has to happen to you to understand, I think. Maybe it's just because I always regarded myself as a good, law-abiding (and not very humble) citizen, who did things the Right Way. I don't know.
What I do know is to this day, I get anxious when someone even mentions the police, let alone when they show up.
For the love of God don't ever, ever ever ever ever talk to the police. If the police want to arrest you they will arrest you. Talking can only make it worse. I thought I was being polite and helpful. It doesn't matter.
The former sheriff of a nearby county (now a felon) said he had the job because he loved arresting bad guys. They will see bad guys everywhere they can.