I’m in the crowd who’s gone from favoring the death penalty to wanting it abolished because of the frequent appalling mistakes (and the vast economic/social/racial biases). Age and maturity helped change my view. I also realized that if you are really wanting to punish someone, life in prison (or longer) seems far worse than death.
However, if I have to live in a country with the death penalty, a silver lining will be Dzhokhar Tsarnaev’s inevitable execution.