RE: the initial Sandford police report. I think the prosecutor is going to have a tough time getting around the initial police contact who said:

“…While I was in such close contact with Zimmerman, I could observe that his back appeared to be wet and was covered in grass, as if he had been laying on his back on the ground. Zimerman was also bleeding from the nose and back of his head.”
…
“..While the SFD was attending to Zimerman, I over heard him state ‘I was yelling for someone to help me, but no one would help me.’”

All of which was before anyone talked to the 2 eye witnesses.