God's law is for man to "Choose Life". While something like a cop who kills a serial killer who's trying to kill him, or running away to kill another day might be forgivable, killing a helpless human being no matter how evil is murder. Counting the laws and appeals involved, it's cheaper for life in prison, along with the likelihood that innocents are executed...

"It seems to me that his only crime is poverty, but he's yours and I don't want to hear any more about this."

So, it is wrong to harvest organs from condemned, again as wrong as it is to kill them. A society that thinks this is right becomes like China, where executions are performed on demand and the 'guilty' sentenced to die are increasingly done so because of profit motives for 'organ tourists'.

And, really, do you want the "Parts" of a horrible killer? Most are wretched junkies or black people that end up being 'convicted' due to poverty. And once in a while, pure evil manages to get caught alive to be executed. Want to have the BTK killer's heart? (assuming the next step will be life imprisonment cases) There's this neat movie; "Body Parts" on that subject. Really, a lot we don't know about how nerves affect the body, how much of 'us' is in our parts.