Is that a serious question?
Your entire OP is leading in that it is making the assertion that need has anything whatsoever to do with the ownership of weapons. You blatantly remove the core reason that justification is pointless here as you do not need to justify a right. Those that want to infringe on it must justify why.
I reject that you give a hoot about the answer to the question anyway since a few posters have clearly answered it and those have been ignored by you in favor of pretending the answers you knew you would get are 'deflecting' or did not read the OP. Lets just bypass the cover and go right to the heart of it and assume there is no justification whatsoever. The next question then is so what? Justification is irrelevant in the exercise of a right. There is simply no way around that whatsoever.
I am not denying the right to own an assault rifle. I wonder about the necessity to own an assault rifle.
In this thread I have heard that it is necessary to defend one's self from an over reaching and corrupt system of government nad corporate power brokers. I have heard that it is necessary to defend one's self against marauding hordes of Muslims and criminals hell bent on invading your house. I have heard that it is necessary simply because it is a right.
But those answers raise more questions. Are there indeed maurading hordes of Muslims and criminals? Could an assault rifle hole off the forces of a corrupt government and their corporate overlords?
The crux of the current debate has been effectively shut down by the semantics of definitions. A convenient means of deflecting the discussion away from real informantion. Much as the debate over the former assault weapons ban was deflected by arguing over the cosmetics of guns rather than the essential questions of lethality and practicality beyond sporting use.
Today we are debating the merits and practicality of arming teachers. The majority of advocates say teachers should have concealed guns.
That drives this question: if it is necessary to have an assault rifle for personal defense, why is a concealed weapon deemed adequate to defend a school room? Shouldn't a school room have the best defensive tools available? And if an assault weapon is necessary for personal defense, shouldn't an assault rifle be slung over the shoulder of a classroom sentinel?
And that prospect drives this question: Is that the society we want to raise our children in?