There was no abuse.
Again as a lawyer, you would know that a perception, whether true or not, can form the basis of a motive. Just because the murderer's father and brother said there was no abuse doesn't necessarily mean that it is a fact. Even if there was no abuse, it doesn't mean that the mentally-ill person couldn't falsely believe that abuse has taken place and act on it.
Exactly how can you back up that statement? Source? Link? Shunning is abusive whether it is approved by the mormon leaders or is done at the members' own discretion. Do you claim to be a psychologist as well as a lawyer?
This man obviously felt abused badly to go to the extreme that he did. Whether you approve of his motive is of no consequence. It caused two deaths which I deplore.
I hope you keep posting in this vein, so that more and more of the FReepers who think mormons are "just the NICEST people" can see the venomous hate dripping from your keyboard.