Murder is the killing of an innocent being.
A person who commits such a heinous crime is guilty and as such has forfeited his right to live.
This is all rather basic stuff, really.
If the best rebuttal you have is to nit pic at the semantics of my argument, it seems you don't have much of an argument yourself.
Anyway, to reply to your issue in semantics, murder might not be the correct term depending on your perspective (murder = unlawful killing... which implies that there is a law which is super awesome and all knowing and that if it is within the law = ok, outside = bad - also, when you say innocent, innocent of what and by who's standards?)
But anyway, let's not go into a tangent on the morality of the law or the relativity of morality.
Let me just finish addressing your nit picking before going back to the argument at hand: lets not say 'forgo the right to live'. It sounds like the PC bullshit people hide behind so as to not face the harsh reality of life.
So, let's call a spade a spade, and when I said murder him, just replace it with KILLING. Because that is the reality. You enjoy knowing he will be killed. I enjoyed him being raped.
So your argument is your enjoyment is ok, while mine is warped. Correct? Why?
And please don't talk to me about your position being humane because he doesn't suffer. That is beyond absurd. Of course people will suffer from knowing they are going to be killed. And before you say one is mental while the other physical, let me just point out that all pain is mental.
So continue feeling superior to us 'warped creatures' (i.e. the alien other) if you like, but if you want to be honest with yourself, you will recognize the sick vicarious nature that is in almost all humans; yourself being one of us if you admit to enjoying knowing people will be KILLED (not 'neutralized', not 'forgoing the right to life' not any other bullshit word designed to hide the meaning of what is being said)
Which reminds me:
[ame="http://www.youtube.com/watch?v=vuEQixrBKCc"]George Carlin - Euphemisms - YouTube[/ame]