The justice (and not only "if not guns then peace and ever so"):
It may very well be that the torture rates of USA are significantly lower because with guns people are able to revenge. In other parts of the World, one is in lack of this and therefore people commit the most awful acts against one another (more so than in USA, not an angel-country itself).
Therefore, I'd like you to consider
* guns equals less torture (less molestation and traumatizing of children)
* no guns equals more torture than if guns are present like in USA, the only country where guns are present to this degree.
Do not forget, please, that USA has become the most powerful nation based on its virtues and one of these virtues is the 2nd amendment right, the right to own arms (preferably only small arms).
One thing is to die from a gunshot, but a whole other thing is to die from torture, perhaps taken to the most extreme, both in terms of time and of mental pain. Torture must be seen as straight evil in today's World when even the military issue may be seen as excess due to overwhelming power from NATO and UN (UN Sec. Council).
Our legal systems worldwide aren't perfect, surely. But the system in USA edges more toward a desired system than in rest of the World.
Just think of where you want to live. Do you want to live in a poor country? One hears of no torture in South Africa, but is it really so beautiful? And so on for every other country...
The victims to gun violence must be seen as a sacrifice for keeping torture and widespread abuse of children to rather low levels. It could be European levels and they are not good at all!
From a citizen in Europe, a system much overrated in terms of legal systems.
Note: There's a further question for this 9-killer shooter. Should he see the death penalty or how long should he sit in prison because of this?
(To be edited.)