Why does insanity qualify a monstrous individual for a free pass to a cushy hospital and early release? If this was a rabid dog it would have been put to death. So it should be with mentally deranged people who kill. They must be put to death posthaste.
Following your logic:
We experiment on animals, why not humans??
We can clone animals, why not humans??
We eat animals, why not humans??
We keep animals as pets, why not humans??
We kill animals when they are sick or old, why not humans??
You are comparing apples with oranges, FRiend.