Good luck in your recovery!
Absolutely agree it will not be the main reason for what he did, there has to be more to it than that, but I just feel there is enough science behind it to consider that it could be a factor amongst others.
I do not believe a "normal" person who ended up with CTE would become a murderer, but if there are already underlying Demons then how much could a heavily damaged brain impact on their state of mind? An unanswerable question I suppose.
PS Don't F With Cats is another great Netflix documentary if you are looking for something to watch, lol.