... America, you need to stop being so backwards on so many things.
At least your Supreme Court has brought you kicking and screaming on the topic of gay marriage (which we Aussies are frustrated at our current PM's lack of willingness to budge on), but every other civilised nation on earth has abolished the death penalty, and for good reason - it doesn't accomplish any of its aims, and in the meantime it's just plain wrong.
It's wrong when the person is a drug smuggler, as with the "Bali Nine" Aussie guys who were murdered (death penalty is murder) by the Indonesian government, and it's wrong when the person is involved in a terrorist attack as in this case. It's wrong, no matter what the crime. The only justifications that I've ever heard for the death penalty are these: retribution, lower cost than life in prison, setting the victims' families minds at ease, and discouraging the acts that have it as a punishment. The latter three have all been shown to simply not be true.
For any country with a fair legal system, the costs of all of the processes leading up to the use of the death penalty easily outweigh the cost of keeping the person in jail for life, including the cost of the higher security used for death row, and besides, making a decision on someone's punishment on the basis of what's cheaper is cruel and inhuman. The victims' families are rarely ever actually comforted by the death - it might feel like an end, but the feelings aren't resolved at all by it, in the vast majority of cases. And the death penalty has proven, many times over, that it is not a deterrent - those who would commit these kinds of crimes usually know that they're risking death anyway (even without the death penalty), and discount the issue.
And that just leaves retribution... and no civilised society punishes its citizens (or anyone else) for the purposes of retribution. Vengeance is disgusting. It's a primal, animalistic response that has no place in modern society.
So I'll say it again - the death penalty is just plain wrong. In all cases.