That's might be correct, but it's still naive as the underlying problems are far greater. There will always be troubled families as long as there is injustice, poverty and whatnot. That's what people should be focusing on.
Nevertheless, violence is a fact of life and strongly correlated with a person's economical and social status. A weapon can be your fist, a rock, a knife, a pistol, a rifle, etc. The easier is its to obtain a weapon of greater power the greater the incentive to use it. The easier it becomes, the greater the temptation. The greater the weapons, the greater the damage, the greater the power a person can have. What if you could buy trip mines or hand grenades from a store? Would people use them?
Just look at places such as Colombia. Poverty, injustice and easy accessibility to guns.
Removing guns wouldn't eliminate the underlying problems. Nevertheless it would minimize the consequences, while the actual problems would be worked on.