As human beings, we strive for order, for explanations to enable us to process horrifying information like this.
It is natural to look for a 'reason' for people to do these things, but sadly, there often is no reason that can be offered, either by the criminals themselves, or by anyone trying to make sense of it
That bafflement simply makes the feelings for us, from a distance, feel even worse, more impotent, helpless, and furious.
Emmie's headline says it all.