Child psychologists have gotten us into a lot of the child rearing problems we're in now. The feel good, no red ink, no score keeping bull**** has caused many of the issues we're seeing in the newer generations.
He may have simply shot mom because she was trying to keep him from
taking her guns ... but there certainly could have been other factors.
It's all a guess. I have to wonder why he targeted the school where she worked and kids she worked with. Did he think she loved them more than she loved him?