Whenever you ask for proof "for sure", you're not going to get it... it's the whole subjective reality lens that you gotta try on to see if it works better or not. How do we know anything for sure, anyway?
You know, pretty much all of the suffering we see is man-made, and we blame it on God. We're the ones destroying the environment, we're the ones creating nuclear bombs, we're the ones shooting civilians and suicide bombing school busses over some piece of holy land that they think they can "own", when in fact it is now calibrated to be unholy due to all the blood spilled over it and you can't "own" anything anyway, much less land that belongs to Mother Earth. We already have the technology to feed/clothe/shelther the whole world, but we're not doing it. I don't see how we can actually blame God for any of it... blame him for allowing criminals and cruel dictators and serial killers to be born? For sin to happen in the first place? Even then it was Man who out of curiosity, ate the apple and caused it to happen...
Also, keep in mind the theory that Earth is a karmic/spiritual training ground...it is MEANT to be good and bad, to the extreme. This allows people the complete spectrum of choice in which they wish to align themselves as. That's why many of the sages say the world is perfect as it is, there is no need to change it.
And finally to address your example, it may be a case of negative karmic debt to repay. What if in a past lifetime that kid was the one who was torturing/robbing other people, and now needs to learn the lesson and repay his debt? You have to take everything into context, not just isolate a single incident as good or bad. It's like the yin-yang concept, everything flows together. Karma just so happens to be a natural rule of the universe like gravity, souls here do not get to choose whether its "on" or "off"
unless they're enlightened