SANFORD, Fla. (AP) — Jurors who acquitted George Zimmerman of all charges were guided in their deliberations by 27 pages of jury instructions that included two sections giving them an option to find him not guilty: justifiable use of deadly force and reasonable doubt.The acquittal of the former neighborhood watch leader left many Americans wondering Sunday how the justice system could allow him to walk away from the fatal shooting of Trayvon Martin, the unarmed black teenager whose death provoked a long national debate over racial profiling and self-defense.But the essential criteria for deciding the case came from the court itself, which told jurors that Zimmerman was allowed to use deadly force when he shot the teen not only if he actually faced death or bodily harm, but also if he merely thought he did.And jurors heard plenty of conflicting evidence and testimony that could have created reasonable doubt.Some Martin family supporters may never understand the gap between the legal basis for the acquittal and what they perceived as the proper outcome: Zimmerman’s conviction for either second-degree murder or manslaughter.“There is a difference between the law and what people think is fundamentally justice,” said Barbara Arnwine, president and executive director of the Lawyers’ Committee for Civil Rights Under Law, a Washington-based civil rights group.One of those Martin supporters who had a hard time accepting the decision was Tara Banks, a 46-year-old black woman from Gainesville, Fla., who said the verdict was causing her to lose faith in the courts.“He killed a human being and he walked away from that courthouse scot free. It’s just terrible,” Banks said at a small rally near the courthouse where Zimmerman was tried.Under Florida law, jurors were told to decide whether Zimmerman was justified in using deadly force by the circumstances he was under when he fired his gun. The instructions they were given said they should take into account the physical capabilities of both Zimmerman, 29, and Martin, 17.