Low crime rates is more of a byproduct of lack of reporting and general culture of the people. There are a ton of well-documented case of kidnapping, abuse, and other shady stuff going on. They just never make it big because no one wants to report about it and deal with what that entails.

Humans are going to be humans everywhere, doesn't matter if it's in China, US, or everywhere else. The only thing that really is ever effective against crime is better economic situation, and even that wouldn't get rid of crimes entirely on its own. It's a complicated subject that's rarely ever one-dimensional like "China have low crime rates because they're authoritarian," or something like that.