I didn't know Martin was armed with a piece of concrete sidewalk as he smashed Zimmerman's head? If this is true, it would be case closed in a self defense argument. I never heard of this in the media reports. So from what I have gathered as actual evidence, not circumstantial. Martin was on top beating Zimmerman and attacking him with a piece of concrete. The ballistics show the gun was fired from Zimmerman in a position of being on the ground and fired upward into Martin. The injuries sustained are consistent with Zimmerman's statements. The prosecution's evidence, the voice on the tape, debunked. Zimmerman followed and confronted Martin, here-say. I just don't see how the prosecution can win with circumstantial claims and no hard evidence.