By looking at the genderless conditional probability ('somebody'), you're implying that women like Knox might have male-like murder levels, which is obviously wrong.
No, male-like murder levels would be higher than genderless murder levels. And, if I understand correctly, most of the excess male murder rate involves gang-related violence, which in this case was pretty clearly not involved.
Anyway, I agree that if you are doing pure Bayesian inference you have to condition on all kinds of available evidence, including gender, race, social class, nationality, etc. But we can't expect courts to consider this kind of evidence, for good reasons (avoid creating self-fulfilling prophecies and avoid incentivizing crime within certain demographics).
No, male-like murder levels would be higher than genderless murder levels.
...and what do you think that implies about whether female murder levels are lower as I claimed?
And, if I understand correctly, most of the excess male murder rate involves gang-related violence, which in this case was pretty clearly not involved.
Yeah, no. Think about that a little bit. (Also, please note the irony of responding to criticism about not conditioning by claiming it would be neutralized by further conditioning.)
Here are the New York Times, CNN, and NBC. Here is Wikipedia for background.
The case has made several appearances on LessWrong; examples include: