There are beasts disguised in human form you know. well, even animals kill mercifully, or harm with a purpose - more often for food, rather than cruelty. Not so Homo Sapiens. We harm for enjoyment'
Take the instance of a nurse (functionally literate, educated) who burnt the hand of her 7 years old son - punishment because he missed the school bus. he sustained first degree burns and is now hospitalised. Makes you wonder how she'd treat patients on the job not related to her.
This woman is 29 years old. No excuse of ignorance as in the case of Sean Luke, who was tortured and killed by children (teenagers who do know better as well).
In another case, a man who knew Hope Arismandez took her from the neighbour who was babysitting her while her mother was at work (some commentators seem to have missed this), and killed her.
Abdul Malik was another such person. But this writer speaks more eloquently than me.
I have no idea what the solution is but always, we react after some innocent pays the ultimate price.