Can’t anyone say “GOOD SHOOT”?
I don’t know whether it has been determined that Mr.Zimmerman shot Mr.Martin purposefully.
Mr.Martin may have grabbed for the gun upon seeing it and seized it by the barrel. Mr.Zimmerman, to prevent the gun’s seizure, grabbed the gun by its grip. The shooting may have been accidental.
The police, I suspect, would have fingerprinted the gun after the shooting as per procedure. If not then there is only Mr.Zimmerman’s word against the forensic evidence of a bullet wound.