As said in the previous shooting thread, banning guns will just reduce the amount of gun crime. However other types of violent crime will go up.
Guns make the killing easy and the number of killings high, whilst a knife or a sword will still kill people but a lot less. And there's no stopping the person getting the gun illegally.
Of course a gun is an east and quicky way to go if they killer intends to commit suicide afterwards, but would be a lot more painful with a knife and would reduce the chances of such acts, but only reduce, a person will still do such a thing.