Zimmerman was the clear aggressor up to the point of the end of the tape.
Martin ran (according to zimmerman on the tape). This is action that avoids confrontation and is exactly what I have taught my kids to do should they ever be followed by a strange adult.
Zimmerman has a documented history of violence - once assaulting a LEO, once smacking his GF around.
Martin has no record (except suspension for habitual tardiness).
Zimmerman viewed Martin, in his own words, as a "effin punk", "on drugs", and up to something. Zimmerman said, "these assholes always get away".
These statements indicate a mindset wherein Zimmerman had decided that Martin was on drugs, a punk and about to escape. Except for the escape part none of this was true.
Here comes my opinion...
Based on their actions of pursuit and avoidance and on Zimmerman's attitude about Martin I believe that Zimmerman continued his course and either caught up with or bumped into Martin.
I think that, given the actions that we know of up to this point, Zimmerman was the aggressor and bit off more than he could chew.
This is, to me, a much more likely scenario than a sudden reversal in behavior by both Zimmerman and Martin.
I also believe that Zimmerman will not face charges...not because he is not culpable...but because there are no witnesses to the beginning of the fight.
Also, absent any racial comments by Zimmerman on the tape (he said punk, not coon) there is no "hate" crime. The Feds have no standing.
You may be right and political pressure combined with expedient cowardice may well prove me wrong.
It will be interesting to watch it play out, especially to see how much racial pressure is put on the Grand Jury to indict.
Violation of ones civil rights, gives the feds standing, and the kids civil rights were violated.
He was arrested but both were dropped, and in fact had filed a counter charge against girlfriend. How you can infer smacking his girlfriend around with that is pretty lame, you can get a DV or an assault charge for spitting on someone.