We may need to do some tabooing. My understanding is that "sociopath" is a much narrower category than "not neurotypical"; in particular, I was under the impression that sociopathy involved a lack of empathy. That doesn't appear to characterize Knox from anything else I have come across (there are perhaps one or two anecdotes that you could retrospectively regard as consistent with that assumption, but only if you didn't know anything else -- most information about Knox from her hometown points in the opposite direction).

It doesn't seem to me that there's strong evidence in the other direction, just a low prior of a random person being a sociopath.

Start here, here, here, and here (4:50).

But you may be right in the sense that I may be overestimating P(Guilty|Sociopath).