From what I've read, if anyone was looking for a fight it was the first guy that got shot as there's footage of him trying to provoke other armed people to shoot him, saying things like, "Shoot me nigga!"And that's the case for pre-meditation. If he can be shown to have been there to get in a fight, which all of those things that were wrong with him being there point to, that's a case to be made.
You think that warrant was served willy-nilly? That the local prosecutor's office didn't assess their ability to prove first degree murder as opposed to second?
You think they aren't issuing the warrant to get him into custody after which they will then be looking through evidence for whether he should actually be tried for that? A warrant does not mean they know a person is actually guilty but that they have reason to believe they are.