In part I agree, but in part I do not.
Think back to when the deal penalty was reserved only for premeditated murder in most jurisdictions.
Some idiot breaks into a home at night, looking to steal some stuff. Oops, someone is home, and he then shoots and kills them to not leave any witnesses.
Before the advent of aggravating factors, and attachment of crimes, and the merging of charges, the guy would not get the death penalty. He had motivation to kill the witness in order to avoid being caught.
Levying the death penalty for rape of a child will give great incentive for the rapist to kill their victim, for which they will get the death penalty anyway. But at least if they kill the victim, there is no chance the victim will report or tell anyone.
Nowadays, most states allow the death penalty for a non-premeditated murder when there are one or more aggravating factors, such as forcible rape, or armed robbery ect, are present. The fact that a murder took place during the commission of another violent crime elevates it to a new stature.
It makes no difference if you intended to kill that police officer while you were trying to fight your way out of an arrest. The fact that you committed murder on law enforcement creates an aggravating factor.
This decision states that child rape ALONE is not sufficient to merit the death penalty. The SCOTUS has repeatedly upheld aggravating factors and attachment of crimes when considering capital punishment.
Also note, three Catholic Justices unequivocally supported the death penalty, for which the Vatican has quite often said how it is extremely difficult, or impossible to justify in today’s technology age and modern prison systems