I'm sorry but bull****.
How much time have you spent in prison? I've spent more than a little time in them in my law enforcement past. They aren't as nice as some people think, but they are hardly hellholes. Most inmates are in mid to low security prisons which from what I've seen are pretty orderly and not really that violent. Granted that some hi-sec prisons where they incarcerate the worst-of-the-worst are a different story, but there's only so much you can do with scum. They make their own hell.
Our criminal justice system is WORSE than China's, where they execute dissidents and make the family pay for the bullet?? WORSE than Iran's, where they hang, stone or decapitate girls unfortunate enough to get raped?? WORSE than Saudi Arabia where violations of Sharia can get you stoned or chopped?? That is one of the most outrageously unfactual claims I've ever heard. I'm tempted to ask what you've been smoking.