One other obvious scenario. Weaver was shot twice. once in the side and once in the chest. If it is determined he was shot the second time after he was already down on the ground,and no further threat, that would also be murder and premeditated..
And here is yet another scenario. Since the kid was invited it is evident the families knew one another. There may have been some kind of feud between the parents, weaver was a little league coach by the way. The shooter while maybe at a ball game or in a public bar may have made a statement in the past to someone about, I’ll kill that SOB if I ever get the chance. Just saying, all the above could lead to 1st degree murder chargers.