So in your opinion, without laws, humans would be prone to random unjustified killing? But if its biological, it cannot be wrong certainly. We could just call it collateral damages.:shrug:
No, in fact most people do not think random unjustified killing is right. That is why this feeling is codified into laws, so that killers will be punished. The deterent effect of these laws is debateable, but at least those few people that are completely immoral or asocial are separated from the rest of us.