In my view the answer is clearly the State of Florida.
The sad thing in this case is it will now all get caught up on whether or not George Zimmerman is guilty of murdering Trayvon Martin and was it racially motivated. That is important, particularly to Trayvon’s family and obviously to the black population in general but the much bigger problem is that we live in a world in which a young guy like George Zimmerman can play cop and be wandering around late at night armed, looking for trouble and feeling empowered. Regardles of the circumstances young men wandering around with guns looking for trouble generally find it! I have been a young man (once upon a time) and I have teenage sons. We all know that it easy to get caught up in the moment and the combination of testosterone and adrenalin can be deadly. Young men are over represented in all sorts of premature death categories because of this.
So given all this and the fact that pretty much everyone knows this about the dynamics of young men it just should not be legal for them to wander around armed and feeling empowered to shoot unless they are part of the police or the military, are trained, supervised and held accountable. Even then we still have many problems but at least we have a some controls. The fact that Zimmerman wasn’t arrested because the police had no evidence to dispute his claim of self-defense is the next problem. You should automatically always get arrested and charged with murder when you shoot somebody dead. The assumption is that you have done something wrong in taking another life and need to be held accountable.
It is up to the courts to then decide whether or not you are guilty and run the course of law but there should never ever be any grey area in which it is anyway plausible that there can be no consequence and no public holding to account of the killing of another person. People are often arrested and charged and then found not guilty that is why we have the legal process but we need to let it run its course not neuter it at the outset.
So regardless of whether George is guilty or not it is the laws in Florida that need fixing and it is the State of Florida and its legislators and voters who are to blame for the killing of Trayvon Martin. The stand your ground law need fixing.