Considering that the three Palestinian college kids were wearing that black and white checked neck rag to show support for Hamas, it seems that someone went overboard by using a firearm to object to their support for terrorists killing Jews. Of course, the shooter might instead be a performance artist specializing in irony trying to terrorize supporters of terrorism.
Three arabs wearing Kafiyeh. I would hold off on judgement until you understand what they were doing. Just ‘foolin around’, like they do in Ramallah? He might have been defending himself. What were they doing?