Wish I had mod points for you.
There is no crime, no matter how grave, that justifies capital punishment. Beyond the obvious (yes, obvious - a society killing criminals has no right to call itself civilized) moral reasons, there is the fact that it has been proven time and time again that capital punishment does nothing to deter crime. At all. Beyond this, there is also the fact that the person you're killing might very well be innocent - no court is perfect.
Most of the comments on this story are really depressing - it reminds me of a quote (from, I think, Henry James):
"America Is the Only Country That Went from Barbarism to Decadence Without Civilization In Between"
On a related subject, I'm personally against the very idea of prison - here too, it has been proven time and time again to actually increase criminality instead of reducing it. However, I don't think there is a better system right now, although I believe being forced to home residence with an electronic ankle collar is a step in the right direction - it should IMO be the only option for non-violent crimes, never prison. For violent crimes prison is probably the best thing we have right now, but in that case it should be an open prison, similar to (I think) some in Scandinavia - a prison that is more like an isolated town where you are free to move about and work and have relative comfort. Something truly better than the shitholes we have right now, a "prison" that would actually improve the chances of the inmates being rehabilitated instead of being pushed even more towards crime.
Eventually, I'm hoping technological advances will provide better alternatives (something akin to Iain M Banks' slapdrones, for examples).