It also doesn't mean it wasn't prosecuted effectively. Maybe the actual facts of the case (not media reports) and the rules evidence (the kind used in court instead of the media) were not sufficient to convict.A jury heard the case of Trayvon Martin too. But that doesn't mean either case was prosecuted effectively.
So what should be done about it, lynch the prosecutor, Tar and Feather the jury because you don't agree with a legal result?