I HEARD the prosecutor in the Zimmerman trial ask the jury to bring back a verdict that would "speak the truth."  But no one really wants or expects "the truth" in these trials.  One side seeks a conviction; the other an acquittal.  JUSTICE is how you want the case to come out.  The trial itself parades before a jury the remnants of a case left over from all the pre-trial maneuvering, the motions to suppress or limit the evidence, the delays during which witnesses disappear or lose their grip on what was a questionable memory of events at best.
Criminal events are quick and traumatic.  Potential witnesses see more or less of what may have occurred, then their life experiences, education, and mental facility have a significant impact upon what, months later, is trotted out by the questioning lawyers as the witnesses' "memory" of the episode.  There will always be contradictions; this is natural and inevitable.  Problems of this sort almost always work against the State, as they have the burden of proof.  It is a heavy burden:  beyond a reasonable doubt and to a moral certainty.
So the prosecutor in the Zimmerman case sought to characterize contradictions as "lies."  It didn't work.  Jury verdicts, whichever way they may go, never surprise me.  If these cases that end up going to trial weren't toss-ups to begin with, they would have been resolved with a plea bargain.
Zimmerman was acquitted because, ultimately, the prosecution could not show beyond a reasonable doubt that the Martin kid wasn't on top of Zimmerman giving him a licking when Zimmerman, out of desperation, pulled out his gun and shot him in self-defense.  That Zimmerman had the gun, that he may have profiled the kid, that he didn't comply with the instruction to remain in his car -- that was really not relevant.  The weight of the evidence showed that, at the moment when it mattered, Zimmerman legally defended himself.
To say this was a racially-tainted verdict is to ignore the evidence that was presented.  This was an attentive jury and they were not stupid.  You want to prevent things like this from happening in the future?  Add your voice to those fighting against the NRA.  Tell state legislators to stop creating laws that allow people to carry concealed firearms.  Zimmerman had one because he had a right to have one.  That right is a creature of the Second Amendment gone all to hell.