If it takes a long time, you can encourage him, because the prison conducts an assessment and asks him to make efforts to reform and overfulfil the tasks assigned by the police. You can introduce him to some interesting things between neighbors or childhood friends, remind him of his hometown and have the motivation to go home as soon as possible.
Every festive season, at the end of the year and the beginning of the year, prisoners miss their families more and often write letters, which will make them feel better. But don't tell him the bad things at home, it will affect his transformation.
Besides, all the letters you go to have to be checked by the police, so please don't involve personal privacy.
I hope I can help you.