How can we transfer a person from prison to a mental facility?

I have quite an unusual question. My father in law was convicted of arson about 20 years ago. At trial, there were several references of different people saying that this guy was not so mentally capable of going to trial but we live in a small town and the judge of the time had a personal vendetta against him due to a girl from his high school days. Even the first chief said that there is no way he could have done it by himself due to how the fire started and where was nevertheless he was convicted. He was recently released and taking off his medication and he should be in a mental hospital, not state prison. My question is where would I find a civil rights lawyer that would be willing to talk to us about the case. He was only out of prison for about 3 weeks. Police knew it was a matter of time before he would go back due to his mental status. He is a money maker for the states considering his care and medication while he is in prison but he really needs to be in a mental facility. He was in prison without medical records for over 8 years and denied his medication. I have read several reports in the Tulsa news paper where people are really confused were you even going to trial. I mean he was in court taking off his clothes flirting with reporters representing himself and we will all this was going on. They still let him represent himself and go to trial. I can send links to the newspaper articles if that would be of any help. we live in Oklahoma and would appreciate any help.