Good guesses, and to answer MaryCas: No, this wasn't on the bar exam though I may raise it in a bar.
The answer is along another track and it has to do with Joan. Not only are Sally and Joan sisters, but they are conjoined twins. Sally can't be imprisoned or executed because Joan is innocent and therefore can't be imprisoned or executed.
OMG, I would have NEVER thought that. Of course, how often would that happen. Still, Sally could kill as many people as she wanted to and get away with it?
That would be a landmark case without a doubt.
TIS
"Mankind must put an end to war before war puts an end to mankind. War will exist until that distant day when the conscientious objector enjoys the same reputation and prestige that the warrior does today." JFK
Still, Sally could kill as many people as she wanted to and get away with it? 
