@Meeeh
Caucasian is the all-encompassing term. By most definitions, South Asians, Berbers, and Semites (among others) are not white, but they are caucasian. Hispanic refers to all people of Latin American descent it's an ethnic group.
@UHM
It's not so simple. It's a tragic incident, but Martin was the aggressor. If you feel you're in danger, you need to get yourself someplace with witnesses and call for help. You're justified in using force only if force is used against you.
Zimmerman was probably wrong for following Martin and getting out of his car to confront him, but Martin was certainly wrong for attacking Zimmerman. Throwing Zimmerman to the ground and beating on him gave Zimmerman good justification for shooting Martin, because at that point, it was Zimmerman's life that was in very real danger.
Had Zimmerman thrown the first punch, or trained his gun on Martin, the tables would have turned completely.
The whole thing is a terrible tragedy. Two people did the wrong thing in the wrong place at the wrong time, and one of them paid with his life. But that doesn't automatically invalidate stand your ground laws.
Personally speaking, I sincerely hope they survive the coming political shitstorm unscathed. Like abortions and firearms, they're something you hope you'll never need, but damnit, they're good to have if the need should arise. A person should not have a legal duty to retreat if they're in real and immediate danger. Castle doctrine should extend to every location and situation people find themselves in.