There's a side of retributive justice that has not been raised, but is relevant. It isn't about punishment to the criminal, but closure to the public who endured the trauma of knowing people directly or indirectly impacted by the bombing. Part of the terror was the lockdown of Boston for days during the manhunt. The additional murder while on the run, is the tipping point for me that a death penalty is warranted. Even though it may take years, thats a sooner closure to the case than natural life.
BTW, I just landed in Boston as I write this, so I may be able to post some firsthand impressions of the decision from those who were impacted.
The bolded bit about precisely where the tipping point is for you is similar to the argument for the death penalty for someone who kills in prison sentenced there to life without possibility for parole. Without the death penalty, such additional killings carry no incremental penalty at all. They are essentially a freebie. I do favor the death penalty in certain very limited instances, assuming that the predicate of one having absolute certainty that you have the right killer has otherwise been met, and this case would be one of them.
