Apparently, Martin was beating on Zimmerman for quite some time before he got shot. According to the sources I have read, a witness saw the beating when he took his dog outside for a potty break. The witness first told the attacker he was going to call 911, then he retrieved his dog who was not on a leash, then he went to his upstairs apartment some distance away to make the 911 call. Even while he was making the call, the voice of Zimmerman yelling for help could still be heard in the background. Only when the gunshot was heard did the cries for help stop. The beating obviously took more than just a few seconds, most likely several minutes.
Zimmerman's injuries (bloody face and head) were recorded by the police; however, I have heard no reports of any injuries to Martin other than the gunshot. This leads me to believe that Martin was the attacker and Zimmerman was unable to fight back. Common sense tells you that no man would endure a beating that lasted as long as that experienced by Zimmerman without trying to ward off his attacker. Zimmerman's multiple injuries and the apparent lack of injuries to Martin prove Zimmerman was the guy on the bottom and he was unable to defend himself without using deadly force.
I would like to know if if the bullet passed through Martin's body. This is important because if it passed through it could provide additional information as to who was on top. If Zimmerman were on top, I would expect the bullet to be found right under Martin's body, possible penetrating into the ground or asphalt. If the bullet passed through the body but was not found on the scene, Zimmerman was obviously on the bottom during the beating. I really don't need this evidence since other information independently proves Martin was on top, but I am curious nonetheless.
Fortunately, unemotional forensics will be the deciding factor. If forensics show that Martin was shot at point-blank range after he had been beating on Zimmerman for more than a few seconds with no end in sight, there is no way Zimmerman will be convicted; arrested perhaps for purely political reasons, but not convicted. Hell, this case would be a defense attorney's dream.
There are those who think that Martin was shot as he was running away or perhaps backing off. If this is the case, Zimmerman had no right to use deadly force since he no longer had a reasonable fear of death or serious bodily injury (this is the legal standard for self-defense). However, this could only be true if the ballistic evidence shows that Martin was shot at some distance. I don't have access to the official ballistics findings, but from everything I have read I am certain that the evidence will show that Martin was shot at point-blank range during the time he was beating Zimmerman. The good thing is that the ballistic evidence should be conclusive. Final analysis: self defense.
I can only wonder what would have happened to Zimmerman if he were unarmed. Do any of you wonder the same thing?