A few random points:
1. There is no evidence that GZ was severely beaten. He was probably struck once on the nose. Zimmerman has no reported guarding injuries, and TM has no damage to his hands, wrists, or elbows. In short, there is nothing to suggest that Martin was striking Zimmerman repeatedly at all. No evidence, other than the testimony of the defendant -- a known liar who has changed his story multiple times.
2. There is no evidence that Martin was repeatedly ramming Zimmerman's head into the sidewalk. First, they weren't on or even near the sidewalk. Second, Zimmerman's head does not show the injuries you might expect if this had happened. Third, no blood was found on the sidewalk. Fourth, Zimmerman was bald and it was wet -- making any effort to grab his head difficult or impossible. Fifth, Martin had no blood or DNA from Zimmerman on his hands.
3. Zimmerman's version of events has changed multiple times during the course of all this. Not minor points, or things misremembered, but major aspects of his story. This should be kept in mind when evaluating the few simple points he has stuck with.
4. Zimmerman's story does not match the physical evidence or the witness statements.
5. Zimmerman's call to 911 contains defamatory statements about Martin that Zimmerman has never justified or explained, and which do not seem to match what we now know about the victim.
6. There is, in my mind, a very real question as to whether or not Zimmerman's repeated stalking of this kid automatically negates any claim to self-defense.
7. The bullet trajectory is a big deal. The fact that it was a straight through shot, front to back, indicates that Zimmerman must have had enough separation to position to gun between them -- and this ignores completely the problem of drawing it from that position in the first place. If Zimmerman's story were true I would expect to see an entry wound in the side or abdomen.
IMO