"Wouldn't the more compassionate course be to release Terri from a vegetative existence in the belief you are sending her on to a better life after death?"
Yes.
It doesnt matter what you, me, the husband or even Terri whether she wants to die or not. If I ask someone to kill me, no matter how much I truly mean it, if the person kills me it is murder plain and simple. The most Terri can have done to her is refuse medical treatment, which doesnt include food and water, so in this case it is assited suicide. Otherwise the guardian is knowingly starving a person and therefore a murderer. Call it what you want but it doesnt matter what anyone feels best for her if it goes against the law.
The husband should be tried for murder if she dies from his decision.
Irrelevant. It is a greater sin.
(Denny Crane: "Sometimes you can only look for answers from God and failing that... and Fox News".)