In strictly legal terms, the evidence has not been tried before a court with jurisdiction as a "trier of fact". When someone is arrested, they are charged with a crime, and the game begins with the evidence. A lot of evidence is thrown out for one reason or another that seems to please the judge who is the "trier of fact". In most states, you can't appeal the decision of the court that rules on the facts, you can only appeal on the many other possible issues concerning due process, precedents, and things following from those facts. When someone is arrested, there needs to be some reason for the arrest, some probability perceived that there are facts sufficient to go before a court. If you don't have that much, the defendent can come back on the State with a case charging false arrest.
If new facts or evidence is found afterwards, you need to petition for a re-trial. If it's a capital case, you just can't do that. So a reasonable State will train its police to get enough evidence to convict before arresting the alleged perp. That's the nut that kept Josh Powell out on the lam, and from what I've seen in alleged evidence in the Zimmerman case, he's going to be coming back with a case for false arrest, because Martin got mad, lost his temper, and assaulted the idiot that was stalking him.
But who knows what the politics in this case will go to. Maybe this half-white accused is going to get lynched by a black mob. Says volumes about where the march for civil rights has taken the black community. But it's not the first time the tables have been completely turned in the history of mankind's fragmented self-image. Looks like we're all pretty much the same. . . . when we get the power, we abuse it and trample on other people's rights.
