That's all subjective. We don't know if that blood on Mr.Zimmerman's face and back is from Mr. Martin. We don't know all the details. Did the police conduct a investigation with photos of Mr. Zimmerman. Did the EMT treat Mr. Zimmerman.
Simply saying that because 'blood' was on Mr. Zimmerman proved that Mr. Martin was a treat; it proves nothing. Only that 'blood' was on him.
Probably nailed the kid in the heart ~ but we don't know what the autopsy was. No doubt we will find out when Court TV covers this one.