I am strongly opposed to the death penalty, however in the case of Dzhokhar Tsarnaev, there is, in my opinion, a larger reason to sentence him to life imprisonment without parole than simple opposition to the death penalty or the anguish of the victims at the prospect of facing a long drawn out appeals process, and that is the encouragement his death will give to further terrorist suicide attacks.
Istishhad (Arabic: استشهاد) is the Arabic word for "martyrdom", "death of a martyr", or "heroic death".Heroism in the act of sacrifice" rather than "victimization", has developed into a military and political strategy", often called "martyrdom operations"
Islamist militant organisations (including Al-Qaeda, Hamas and Islamic Jihad) continue to argue that suicide operations are justified according to Islamic law.
I believe that life imprisonment for Tsarnaev will help to discourage future terrorist suicide attacks, while sentencing him to death will make him a "martyr" in the eyes of his fellow terrorists.