I'm not sure what FL's definition of manslaughter is, it can differ state to state, but I fail to see how you assume the criteria was not met. JMO, but following someone who had done nothing wrong other than "look suspicious" while carrying a gun seems negligent to me. At no point has anything been publicized that states Zimmerman identified himself. He was a member of the neighborhood watch, not a police officer or even a security guard. He could easily have said, "Excuse me young man, I'm a member of the neighborhood watch, and I don't recognize you. Can I help you?" But he didn't, and because of his actions, that young man is dead. If Zimmerman had been killed, would Martin be able to hide behind the same law? If someone's following me, then my life feels threatened. Does that mean I can "stand my ground"? Bottom line, if Zimmerman stays in his car and lets the police handle it, Martin's most likely alive today.