China has what amounts to different laws for different people. If the police tried to abduct a party member (any government official) even one that was a criminal and disliked they would need a warrant to arrest them. That's what the law actually requires. For 'normal' people they police will just break in and abduct you, take you to the station and hold you until you sign a confession for something or until your absence causes you to violate some law.
The age old question when the state takes on the only right for criminal prosecution is how do you make sure the government will prosecute government agents. In the US if I stabbed you the fact that you are my victim doesn't give you any power to see me held to a criminal level for my actions, my criminal action is against the state. In theory a grand jury can level charges but they have long be co-opted by the legal system as an unwanted rubber stamping body.
So in China when the police commit a crime, they just ignore it and carry on like the law doesn't actually always apply, so long as they only break the law in accordance to the unwritten rule of law.
Now this doesn't even scratch the surface of the whole culture of bribery, obligation and party politics which is more or less a life's study to really understand. This is why the Chinese see no problem in breaking contracts, cheating and stealing from all their outside business partners. Not because they are outsiders, but because they haven't made the proper bribes, contracts, favors and little retarded signs of face and honor that a Chinese company would have made.
Simply put fuck China, and police the world over. Without corrupt police you can't have corrupt governments.