I certainly do not want to make light of this incident. A young women, Qiao Yunao, described the event with surreal details:
"I saw two attackers, both men, one with a watermelon knife and the other with a fruit knife. They were running and chopping whoever they could."
Pressure cookers, box-cutters, fruit knives: it's the minds of the perpetrators, the choices they make that kill and destroy, what is in their hearts not what they have in their hands. I suppose we could try to pass laws against selfishness, greed, envy, anger, and the like. I think, though, progress is unlikely except at the individual level through strong and traditional families.
Human nature is not always pretty or peaceful or innocent. There is wheat, and there are weeds. Apart from the truth of the Gospel of Jesus Christ, I have my doubts how successful efforts to change that old nature will be.