Unless somebody comes up with some evidence that Martin was "up to no good", I think Zimmerman should be held accountable.

Even with this new eye witness account, we still know that Zimmerman hassling Martin into something that ended with Martin dead.

If Zimmerman had called 911 to report that "he was being followed by Martin", this would be a much different story, but the story we do have, what we know for sure was going on was, Zimmerman was stalking Martin... chasing him... with a gun... and now Martin is dead.

Spin it any way you want.