Barbara,
That would be so sad to have a son who you love turn out to be a killer. I can't understand how a son can kill his family, especially the mother who raised him. I don't even mean cruel and abusive mothers - and unfortunately there are some. But, the kind and loving mothers who have done everything they could to love and care for their children.
I know there are examples in movies, but unfortunately there are too many example in real life, also. Just breaks my heart when I hear of anything like that happening.