I have a question about Chinese legal system?

Monkey man seems to know how this system works. You are arrested kept somewhere that no other person can see or talk to you for maybe 6 or 9 months and after this you go to a trail that no one else can see or know what is said or happens. Hmm, during this time if you were to fall (on your own) and break a leg or arm this might help you to remember you did do what ever they say you did. Or while you were having a drink and watch the latest movies you past out and dropped a smoke on your arm and it burned you pretty bad before you woke this might help you remember the bad things you have done. But if you were really guilty of a crime and the government had proof of this why would the trail need to be behind closed doors? It would be just as easy to convict the guilty in a open court as in a secret court. Why do people get arrested and the government denies for months they have done this if the person is guilty of a crime? When a citizen ask the government to give the rights the law say the people have to them, why do these people get arrested and held for months with no charges? But then why did the government of China give a citizen a pport and let him go to Japan but refuse to let this man come back to his home and this Chinese man live in a airport for a year. He did not break any laws. But the laws in all countries have some bad things they do. But other countries do it in the open.