Sounds like a crazy story...at least what I could piece together. No offense, but it is written all over the place, in a sense.
But from what I could gather, this brother with Aspergers IS a problem! Sadly, when it comes to that type of disorder, there isnt any reasoning with them. What gets in their head sticks in their head (like you said)...and they each have a particular 'subject' they become obsessed with. You mentioned chess and then of course his incessant tattling, that must be his obsession - judicial order. On one hand you gotta feel bad for him, but on the other hand, the lack of emotional feelings must make him like HELL to deal with.