What makes a killer?

Please take a moment to ponder. What could happen to make someone willing to take a life? What would push you to the edge? The possibility of losing a loved one? Or to save an innocent victim?

Could the possibility be explored that mankind has embraced evil or that academia teaches self-actualization and survival of the fittest? If there is no ultimate power subjecting mankind to a moral code; wouldn’t current teachings in secular literature promote killing those mankind views as weak? Wouldn’t it be their duty to snuff out the unfit to prove they are the fittest?   

If it is believed that mankind is the code maker, then you also believe that the fittest make the rules? And if the fittest make the rules, when a fitter individual takes the place of number one the rules of moral conduct may change to fit their desire. This is commonly taught in general education and the world wonders why the nations reflect confusion and chaos.  

Perhaps killing is simply an outcome of this chaos. What do you think?