The plot just keeps thickening in the Trayvon Martin shooting case.  New evidence seems to be popping up every week.  The newest piece of evidence concerns Trayvon's autopsy report, which says he had tetrahyrocannabinol (THC) in his system.  This is the psychoactive compound found in marijuana.  The THC found in Martin's system does not mean that he used drugs the night of his murder, because THC can stay in a person's system for up to 30 days, sometimes more.  

The autopsy report also proved that Trayvon suffered from a gun shot wound to the chest at close range, and one of Martin's fingers had a cut on it, which indicates the two were in a physical struggle.  

Although photographic evidence taken by officer Michael Wagner has proved that Zimmerman did have a bloody nose, and a cut on the back of his head which he says Martin inflicted on him by punching him repeatedly while he was down and slamming his head into the concrete, police still believe that the altercation could have been avoided.  Zimmerman was clearly told by a police officer on the phone to stand down, stop following Trayvon, and wait for an actual police officer to arrive on the scene, however Zimmerman disobeyed that order and continued to follow Martin, which is what ultimately lead to their fight and Trayvon being shot.  

The Sanford police department said Zimmerman didn't have to kill Trayvon, because he shouldn't have been following him in the first place.

"The encounter between George Zimmerman and Trayvon Martin was ultimately avoidable by Zimmerman, if Zimmerman had remained in his vehicle and awaited the arrival of law enforcement or conversely if he had identified himself to Martin as a concerned citizen and initiated dialogue to dispel each party's concern.  There is no indication that Trayvon Martin was involved in any criminal activity at the time of the encounter."

Note how the police stated Trayvon was not involved in "any criminal activity at the time of the encounter."  That alone indicates that Zimmerman took things way too far by shooting and killing Trayvon Martin.  Whether Zimmerman was being beaten by Trayvon prior to the shooting or not, the confrontation didn't have to occur in the first place.