He hasn't been a criminal for a very long time. He more than payed his dues as well when he was unconstitutionally held in solitary confinement without bail. Reducing a man who has done so much to something so trivial as this reflects poorly on you alone.
My dad has a real PhD in aerospace that he got from one of the “brand name” schools. He doesn’t have that diploma hanging in his office. Instead, he has a framed fake PhDs from “Thunderwood College” [1] framed in his office, because he thinks it’s funny.
I think he feels like having a fancy title doesn’t fundamentally make you “more right” about something, and not having a fancy title doesn’t make you “more wrong” either, but he feels that people treat you like you’re smarter if you have a doctorate, so he never brings it up (outside of his resume and the like).
It can also come up in a more formal social setting if the Dr. prefix is on place setting or RSVP list. Before I was married I used to always RSVP with doctor just because I hated the Ms. prefix.