That last sentence is the key. There are some cops that are assholes, just like every other profession. But most just want to be treated respectfully and will show respect right back.

I do plain-clothes investigations, so I’m not out on the beat dealing with shitheads, but I can’t tell you how many times I given a cigarette to a guy that was just a decent human being during an interview. Not as an inducement to talk, but just because I know that it’s the last one they’ll probably have for a long time. More than a few times I’ve even had people admit to their crime just because I was nice to them.