The “Need” is up to every American to decide for herself or himself.
Not the Mayor or city council.
When I watched the Boston police department’s operations after the marathon bombings I knew Boston was not a constitutional city. Forcing homeowners from their homes at gunpoint was a travesty. I don’t care what the motivation. If these guys would have robbed a bank and killed and wounded people would this type of manhunt be justified? If I were one of the residents forced from my home, I think I would have brought a lawsuit. Why am I not hearing of any?
The "Need" is pretty clearly spelled out in the Second Amendment.