@sozobe,
Addendum -- at least that was what I read in several articles, but when I went to look that up I found some stuff that calls into question the cause-effect part of this. (As in, I won't go so far as to say that he only wore the hoodie up when it was raining.)
Obviously even if he had it up because he wanted to look cool and not just to keep the rain off of his neck, that's no reason to shoot him.
In looking that up though I found such a wide range of things -- I'm thinking of the Tyler Clementi case and how that was pretty quickly put into a pigeonhole that I don't think was really accurate, so I'm trying to just wait and see a bit, although the info
so far seems pretty damning re: Zimmerman's actions.