(CNN) -- Trayvon Martin went out to buy some Skittles -- and was shot dead before he made it home. The case is horrifying, maddening, grotesque. And -- perhaps worst of all -- there may be nothing Florida law enforcement can do about it. As the world now knows, the 17-year-old Martin walked to a store in Orlando to buy some snacks on the night of February 26. George Zimmerman, a volunteer Neighborhood Watch captain, thought the boy looked suspicious and called 911. The 911 operator told Zimmerman to keep his distance -- police would be sent -- but there was a confrontation between Zimmerman and Martin. Martin was killed with a single shot to the chest. Florida authorities have not arrested Zimmerman, and federal authorities recently joined the investigation.
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Jeffrey Toobin: Trayvon Martin, 17, was shot dead out buying candy in horrifying case
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"Stand your ground" law allows killing if shooter feels "reasonably" threatened, he says
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Toobin: Law means alleged shooter's killing is justified by his own perception of threat
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Trayvon no longer here to give his side, Toobin says
In this case, then, the question is whether @placeholder was in such a place and felt reasonably threatened.