We've already spoken about that here, but I'll repeat it. I suggest you sound the words out so you don't miss it this time.A "governmental" role is different from a "federal government" role. And yes, the prohibitions against the use of force against others, except in self-defense, but Zimmerman is claiming self-defense under applicable state law so . . . yeah, what's the legitimate federal government role here from the Libertarian perspective?
It depends on whether you believe the rights of the kid who were shot were violated. Again, the lowest effective level of government necessary to protect the rights of the individual against aggression. If the local government is ineffective, the State should step in, if both the State and the local government will not protect the individual's rights then, however unfortunate, the Federal government should step in. The rights of the individual are paramount in libertarianism. Pretending we haven't explained this to you several times before makes me think you are being a bit disingenuous in your argument.