RKMBs Forums .::Important::. Politics and Current Events 17 year old Trayvon Martin shot by Neighborhood watch guy Zimmerman

I'll grant that Zimmerman followed Martin. That's not new information. You can hear in the 911 call where he jumps out of his truck (you can hear the bell of the door and the door open and close, and his rapid footsteps) and says to the 911 operator "He ran..." At which point the 911 operator asks "are you following him?"
And Zimmerman answers yes.
And the operator say "Okay sir, we don't need you to do that", and I can't recall Zimmerman's response, but I think he just acknowledged "OK".
He followed long enough to give Martin's location to 911, and then by his account broke off pursuit and walked back toward his truck, when he was blindsided by Martin.

I'll concede that we don't know for certain who started the fight. But if Zimmerman threw the first punch, why was there no evidence of bruising or injuries from punches on Martin?

I would fully expect Martin's girlfriend on the phone to give an account favorable to Martin, and incriminating toward Zimmerman. All she heard over the phone is Martin's version, and she heard sounds that she could interpret to have come from either person.

The prosecution has no case because the evidence is at best circumstantial, nothing clear. And the injuries to Zimmerman, with no apparent bodily injuries to Martin, indicate that all the fighting was done by Martin, and all the defending by Zimmerman.
To prosecute Zimmerman, the D.A. has to prove that Zimmerman did not act in self-defense, and shot without provocation. Zimmerman's injuries show justifiable cause for him firing in self-defense.

And there are forensic evidence and witnesses who either back Zimmerman's account, or at worst don't contradict it.

As I've said prior, I say all this based on what has been made public so far, and we all know there's more evidence that could tilt it either way. But as I've said, at this point I lean toward believing Zimmerman.
If forensics had shown Martin was shot at a distance of 10 or 12 feet, I'd say it hurt Zimmerman's credibility.
If Zimmerman had no broken nose or other injuries, I'd say the fornsic evidence likewise incriminated Zimmerman as not acting in self-defense.
But they didn't.