Recently the choice of "life without parole" became an option for juries in Texas, so there is a chance that the case will not end with the death penalty. Within the last month someone locally was given that sentence after killing someone when the state wanted the death penalty. So it does happen.
As far as the idea that the death penalty is somehow just more violence and has some sort of moral equivalence to murder or abortion, I have to keep in mind a couple of points: First, neither the fetus nor the murder victim has done anything to deserve being killed. The murderer has earned the penalty. In this case, assuming the facts being reported are true, he has earned it several times over.
Second, the inherent sense of justice can justify the punishment. Would it have been justice to allow the Auschwitz guards to live until old age given what they had done? Would it in this case? A jury who will have to endure hearing the details of what happened will have to decide.
If we meted out merely revenge in full measure then we would be devaluing life, including our own. The death penalty, in extraordinary cases however, is justice. That it must be carried out in accordance with the constitutional prohibition against cruel and unusual punishment restrains the passions of the community and prevents defendants from being treated the way they treated their victims.
In Texas a plain old-fashioned murder cannot get you the death penalty. There have to be specific aggravating factors to get there. One of those is murdering a child. I don't know of any excuse for that crime, unless the defendant is truly insane and does not realize what he or she is doing.