I've got my ambiguities about capital punishment in the first place. Sometimes it seems like justice; other times it seems like hypocrisy; most of the time, just or not, it seems like the hardest possible thing a judge or jury can decide to have done to anther person. There is nothing simple about the death penalty.
On the surface, the case of Zacarias Moussaoui would seem to be the most unambiguous, easiest, most cut-and-dried death penalty decision imaginable in the United States. I'm sure a huge number of people see it that way. But I would argue that, if anything, Moussaoui's death penalty eligibility is even MORE complicated than most.
For one thing, this is not Nuremberg, the Moussaoui trial. This is a show trial. America so desperately needs to find and punish a 9/11 perpetrator that we are potentially executing someone who WASN'T on a plane, WASN'T in New York or Washington or Pennsylvania, wasn't even selected as a second-string terrorist hijacker, and at best, might (MIGHT) have prevented 9/11 if he had told what he knew. That last is a serious crime, of course, but it's technically closer to perjury. We do not put people to death for perjury in this country.
Much of the case for death, of course, is predicated on Moussaoui's confession. However, Moussaoui has made and contradicted so many statements, changed his story so many times, and done so much grandstanding and propagandizing and flat-out demonstrable lying... well, at this point how can we take ANYTHING he says seriously? The answer, in this case, seems to be that he is saying what we want to hear, so we want to believe it. But I frankly don't trust a freakin' word that Moussaoui says, even if he's taking responsibility for something so big.
The man clearly wants to make huge statements about jihad against the United States, and how can we be convinced that his guilty plea and his sudden "I was going to be part of 9/11" admission isn't some extension of that? Does anything the man has said establish credibility on his part? (For that matter, does anything he's said establish SANITY on his part?)