I'm guessing he's dealing with a lot of emotions right now. Getting out of prison after three years, that isn't an easy transition. If possible, try to get him to talk to a counselor about things. He probably doesn't feel comfortable talking to you because he doesn't want to put it all on you. He may also be afraid of seeming weak. You don't know what kind of experiences he had in prison and some of them he may just be starting to deal with.

Try to get him to talk to someone. Also, it is important to just be supportive and understanding. Tell him that he can talk to you about anything. If he opens up to you, try not to be judgmental, just listen. Remember that this has nothing to do with you.

Good luck.