Normally, I would not explicitly advocate for a death penalty. Sometimes I feel that the decision is too permanent, or that it would be better to rehabilitate the criminal.
In cases like this, there is definitive proof of the crime. In addition, I don’t foresee any feasible way to rehabilitate him and turn him into a productive member of society. Any available rehabilitation facilities will be more efficiently used to treat other criminals, such as those who commit minor crimes are are thus more easily rehabilitated.
So, basically, we have two choices: lock him up in prison for the rest of his life, or execute him.
In this case, I am okay with the death penalty. Earlier in the thread, someone said “I think [the death penalty] is too quick of a punishment. Life in prison is much worse.” It is on this basis that I prefer the death penalty. We are absolutely confident that the person is guilty, so why bother drawing out the punishment? Otherwise, we are just keeping him alive for the sake of punishing him for a longer period of time. To me, keeping him alive for the sake of watching him suffer is simply another form of the “blood lust” that so many people talk about.
As far as I can tell, the prison system has three possible goals:
1) Rehabilitate the criminal so that he does not commit more crimes
2) Serve as a deterrent to prevent other people from committing crimes
3) Isolate the criminals as to protect society
With cases of extremism, objectives one and two will not be accomplished in any sort of efficient or reliable way. Both the death penalty and lifetime imprisonment will meet objective three. If there is overwhelming, non-circumstantial evidence of guilt, then the death penalty is swifter, and possibly even more humane.