MIAMI (AP) — George Zimmerman persuaded police not to charge him for killing 17-year-old Trayvon Martin, who was unarmed. Now that he's charged with murder, he'll get to ask a judge to find that the killing was justified. And if that doesn't work, he'll make that same case to a jury.Martin's killing has unleashed a nationwide debate about the so-called stand your ground laws, like the one invoked by Zimmerman. Some people claim they foster a vigilante mentality. But an Associated Press review of federal data doesn't seem to bear that out.The number of justified homicides increased from 2000 to 2010. But the statistics reported to the FBI aren't comprehensive and are based on voluntary reporting. So they can't serve as ironclad evidence that expanding the stand your ground laws affects the number of justified homicides.