This kid was an imminent threat of grave harm or death to everyone there. If the taser misses or the prong doesn't set or he's high on pcp or wakka then he walks right through the taser and could kill someone. Employing the firearm after the kid disobeyed direct commands and continued to impose an imminent threat was the right course of action IMO.If the cop had a tazer, you could try that first, but to be honest, I would have shot him as well.