Re: What I don't understand is, what does he stand to gain by her death that a divorce wouldn't do?
According to her parents who are close to this story:
He stands to gain by not being "discovered" in his involvement in her "collapse." There are serious questions about what happened to cause her to collapse as there was never discovered in tests the "chemical imbalance" that the news media always falsely reports.
He is so afraid that she will be able to implicate him that not only does he want her out of the way, but he took care that she would Never receive rehabilitation in order for her not to recover and attest to what happened.
He also has said that he wants her immediately cremated after her death - (which may be against her religious beliefs).
Many people believe that he wants that so there will never be any evidence to convict him if he was involved.
Most of the money he received from the lawsuit for Terri's therapy has already been spent - with a lot of it going to his attorney (a big right to die advocate).
Cremation before a funeral is forbidden under Catholic rules from what I understand. But IIRC Michael has gone further as to say there'd be no memorial service of any sort.