Little known fact: You can't harvest organs from someone who is already dead (i.e. a cadaver).
All organ harvesting must come from a live person, never from a cadaver.
Bonaventure, as I understand, it is not ALL organs, but only single unpaired organs, which must come from a live person.
Though I would think that the fresher any twinned organ, say a kidney, the better would be the result. Which would be a further enticement to kill for a greater success rate.