Well, I don't believe in Hell or Heaven; I just think they're metaphors that make people feel better. We're all placed on this Earth to help the Universe experience itself through us and go forward. Unfortunately, there is darkness and light, and sometimes the darkness makes itself present in the evilest of ways.
We are all at the mercy of our families and society, and, for some, this can be a bad time. No one just kills their own mother and then drives off to shoot 26 innocent people. He was moulded into that monster by his experiences growing up, which is sad in itself. I'm sure his past will be revealed in time and I expect it'll feature horror films, violent games and all the other crap the sensationalist press like to use to sell papers to their flock. But, when he was born, he was an innocent vessel and was corrupted from the outside in by his experiences growing up.
What he did was evil beyond imagination, but he was human like the rest of us. Society is the problem.