Who's fault is it really?

As we all know about the tragic killing of 27 children and teachers. The mother of the murder admitted to giving her son gun (shooting lessons) as a way of bonding. in itself, you know your children better than anything in the world, she knew her child was not fully stable d mentally to teach him how to shoot a gun. My heart goes out to him and his family because people like that all you can do is pray for them and move on. I do sincerly think that  he was out of his mind and that is no excuse, but there's no need for us to hate him because of something he did. I think we can be hurt and have an oppinion about the situation, but there's nobodies place to condemn him. His mother simply wanted to bond, I do agree that they could've talked and maybe a movie date would've been sufficient, but hey everybody has there own hobbies. It just sucks that this hobby killed 27 people.