The criminal system isn't for punishment. It's for reform. It's not to 'get back' at people, it's to help integrate people back into society and act as a deterrent to stop crime in the first place. You're not trying to 'execute this fucker and others like him', you're trying to figure out what's wrong, how you can reform (if possible), and deter other crimes like it. If you're just executing it's a hell of a deterrence, but you're not reforming at all.
Remember the Oslo masscare? Read up on the perpetrator and his sentence. http://en.wikipedia.org/wiki/Anders_Behring_Breivik
There's a big difference between somebody who's medically declared insane and a member of a terrorist organisation who killed people as his masters wanted for the sole purpose of creating terror.
The death penalty is the ultimate irreversible penalty. Don't you think it's better to give people life in prison instead of death.
You should read up about the death penalty as a deterrent. Do you really think Ajmal expected to even get out of the mission alive? Do you think he didn't know about the death penalty if he managed to escape alive.
Every person ever convicted is, in theory, because there was enough conclusive proof. Mistakes will always happen.
To me, that's absurd on its face. Such persons are beyond reason. Don't forget, amongst this group are suicide bombers.
In the U.S. at least, its widely accepted that the death penalty is not a deterrent for murder, much less terrorism.[1]
[1]http://www.deathpenaltyinfo.org/files/DeterrenceStudy2009.pd...)
Its one thing to die a hero another to sit in a cell for forty years in your own filth.
You may argue that it is a false dichotomy, but I disagree, because the people who will kill to get their compadres released will adjust their tactics until they find the lever that works.
I agree that it would probably be fairly tough to institute in a democratic country. But I think it could be doable in a reasonably (but realistically!) rational country. The long-term effect should be a vast reduction in the quantity of kidnappings, since you render them ineffectual.
Such policies are already implemented sporadically. Look at various navies' responses to Somali pirates and their hostage-taking, or the way the US negotiates (or, rather, doesn't) with the occasional terrorist who kidnaps a US citizen and threatens to behead them.
For example, right now, in one of India's jails lies a man named Ajmal Kasab. He is one of the terrorists involved in the 26/11 attack on Mumbai. He was caught on tape mercilessly killing people with his AK47.
If you do away with the death penalty entirely, how do you execute this fucker and others like him?
http://en.wikipedia.org/wiki/2008_Mumbai_attacks
Edit: A lot of people asking similar questions. So I'll just answer them here.
Being identified by eye-witnesses and being caught on camera are not the same thing. People make mistakes while remembering. Cameras don't. Further, he was apprehended by the army/police in the middle of his killing spree. There is NO WAY it was someone else.
Handing him a life imprisonment just puts the system at risk. It will just lead to terrorists resorting to kidnap to release him as has been done in the past. A well known example: http://en.wikipedia.org/wiki/Indian_Airlines_Flight_814