The parents need to be held ultimately accountable. If you have brought up a child who thinks that repeatably booting someone else in the head in is in any way normal or acceptable, then that needs direct intervention with corrective measures on the child and parent.
Its absolutely mindboggling...
Those kids ARE behaving like feral scum though. Unprovoked, unwarranted, pointless blind violence. I would be utterly mortified and ashamed beyond belief if one of my children had ever behaved like this. I don't think I'd ever get over it.
Once identified, it should lead to the prosecution of...