As stated before it's all pretty simple as far what's relevant--it all comes down to how did the two come together and who initiated any physical confrontation and what was said between the two people before there was any physical confrontation. Most importantly what is the forensic evidence? Is the gunshot wound to Martin point blank or further away--at what angle. Is there DNA evidence on the clothes, parts of the individual such as under the fingernails, on the gun and or holster of Zimmerman--fingerprints also. What injuries did Zimmerman receive and what injuries if any other than the gunshot wound did Martin have. If Zimmerman had injuries what treatment did he receive and by who, when and where? Did the local cops take photographs, DNA samples, forensic testing, confiscate for evidence clothing worn by the participants or other evidence. What exactly did Zimmerman officially tell the local cops. What was he asked? What did they record, take down, catalog, and do to preserve the crime scene. What does the entire 911 tape say. Considering the time that has elapsed since the homicide and the fact it was raining that night unless the local cops did their job as set forth above the whole case can be seriously compromised. It is my speculative impression that there is a high likelihood that the locals didn't do exactly a Sherlock Holmes job. If that is true that would potentially seriously compromise any investigation into what actually happened and why.