"Joseph was a time bomb waiting to go off. I don't blame him," she told The Independent. "But it is hard to believe that I am not going to see her again, that she is not going to just phone me and say, "I am back'. I don't want to be consumed with anger and hatred. I just want to know why this happened."
Ms Morrison, 30, said she wanted answers to why there was no proper risk assessment carried out on Joseph, why he was able to refuse medication for four months, how he was allowed to get hold of kitchen knives and why her mother was allowed to go into such a dangerous situation alone.
"It is ludicrous. Why was it not reported that he despised women and had delusions about my mother wanting to torture him? Surely somebody else should have been sent in to see him. There was no reason to provoke him even further. It was obvious he was going to explode. Unfortunately for me it was my mum who was in the way."
Ms Morrison said her mother was a dedicated and passionate advocate for the mentally ill, who worked from dawn 'till dusk and had refused promotion in order to remain in front line services.
"The only consolation I have is that she died doing the job she loved," she said.