There are lots of disorganized academics who aren't all that competent in real world activities. BK definitely had problems completing previous schooling, and I personally believe there's no evidence that he ever lived outside the parental home. He spent a lot of time online and in reading/thinking.
Almost anyone can snap under stress and behave in ways that look crazy. However, this crime took some planning, which I believe he did. He just didn't know how his own psyche would operate under such extreme conditions. It's a lot like thinking you know what it's like to go through labor and delivery, before you've done it. Or, for that matter, what a broken leg feels like when you've never had one.
I was thinking he probably had some earlier crimes under his belt, but now I'm not so sure. He does look like a complete newbie.
I am speaking of the categories typically used by the prosecution and the defense.
The prosecution will claim that evidence is incriminating, the term "exonerating" is used by the defense as a general term for all evidence that helps their case. When discovery happens, most discovery documents mention that all exonerating or potentially exonerating evidence discovered by the prosecution must be produced and given to the defense, as a matter of due process.
It is related to the dictionary definition, but I'm using it in the sense of a process of legal discovery. Perhaps I should use the word "exculpatory" instead, but thought maybe that would pose problems of comprehension.
Here's wikipedia's definition of the Brady rule:
//The
Brady doctrine is a
pretrial discovery rule that was established by the United States Supreme Court in
Brady v. Maryland (1963).
[2] The rule requires that the prosecution must turn over all exculpatory evidence to the
defendant in a
criminal case. Exculpatory
evidence is evidence that might
exonerate the defendant.
[3] (my emphasis, complete text with active footnotes posted just below).
en.wikipedia.org
If the evidence *might* exonerate (show innocence) then it is exculpatory as well. And must be produced if the prosecution has any such thing.