This research states that incarceration doesn't reform a criminal. He has spent almost half his life in prison but the time there didn't reform him, he continues to commit crimes. He is probably never going to be a law-abiding citizen by now, if he most likely hasn't finished high school, never had a real job nor could get one with his prison record.
The research doesn't explain neither why he started committing crimes, if it was because he has some form of mental illness, or perhaps because of a poor upbring and background, the lack of hard-working role models. If the reasons of why he started committing crimes were treated, maybe he would stop doing so.