Chris will be an interesting case in terms of if he's fit to stand trial or if he knew what he did was wrong. I believe he knew what he did was wrong, just like anyone who rapes another person knows that having sex with someone who doesn't want to, isn't able to give consent or fight back is wrong. But then, some of the things he's done over the years point to him not being of sound mind (the self-inflicted taint operation is what spring to my mind). It will be interesting to see what unfolds. Plenty of trans people hate their genitals, but they don't cut themselves, they have the presence of mind (and sanity) to know that doing something like that poses a huge risk to their health and their chances of getting any gender reassignment surgery in the future.
Can he separate fantasy from reality or is he simply so far gone that he can't? Is he smart enough to put on an act that can convince both the State, a judge AND any medical professional that examine him that he didn't know fucking his own mother was wrong, especially when she can't fight back or say no (assuming she did)? Insanity is a legal term, not a medical term, so they'll have to suss out what's what. Whether he's legally culpable or not, I don't think he'll be let out. He's too old to rehabilitate any time soon, it will take years for him to unlearn the behaviors he currently has, if he ever does.
Part of the intrigue of Chris for all these years is we've never really known a lot of those things. How sane is he, how far into his little fantasy world/world of 14 Branchland Court is he that reality as ceased to be...?