Playing Belsavis and discovered most of the prisoners are descendents of criminals rather than criminals themselves, how did this happen? Is it Canon? And why haven't the Jedi intervened on this travesty of justice?
Likely because the Republic uses it as a prison for dangerous Sith Lords and criminals, the Dread Guards for example. It is considered C-canon, if you don't know what that is you should look up Lucasfilms canon guidelines.