There's a little more to this story, the media just only tells half the details -.-
Kid A told his parent he was going to play in Kid B's backyard. Kid B told his parent he was going to play in Kid A's backyard. Obviously they can't play in both yards at the same time. They were planning on going elsewhere the entire time. Don't get me wrong parents are some of the blame; they should have followed up and warned the kids about the items they owned.
All were charged with disorderly conduct as well as fleeing arrest.
Again, the reason we so desperately need more recognized legal fields as well as the vitality of educating new players (not just the younger crowd) about proper gun safety and etiquette.