That's because we have a Constitution. My daughter spent 6 weeks studying in Russia earlier in the summer. She personally witnessed petty criminals like purse snatchers, pickpockets, and shoplifters being beaten senseless by Police officers, then left bleeding and lying on the street. It reminds me of training puppies. Once you smack them with a newspaper a couple of times, they learn.
Rather than being aghast, she suggested that we could reduce crime in the US by adopting a similar strategy.
I do not advocate the same sort of thing in the United States. I'm just pointing out that it is the natural progression of things when authorities are allowed to selectively enforce the law.