The death penalty and revenge justice is not appropriate underany circumstance.
Bullsh**t.
The death penalty is plenty appropriate for mass murderers, rapists, and other such people who prove that they're incapable of living in society as human beings rather than animals. I don't care if it's 'revenge' justice. The punishment should fit the crime, and death is warranted for all those who engage in activities which inflict harm upon society itself.
That being said, I oppose the imposition of the death penalty by the United States government, so obviously I don't think Tsarnaev or anyone else currently sitting on death row should be executed. Not because some of them aren't guilty, but because the United States government does not have the kind of moral high ground necessary to pull the trigger, tighten the noose, or flip the switch.
I do think he'll end up getting it, which is unfortunate because he'll be yet another case the U.S. government can point to and say that 'justice was served' all the while it continues to create the conditions which produce terrorists like Tsarnaev at home and abroad.