Yes it is. Either the mayor supports state-sponsored revenge or he doesn't.
A lot of people oppose the death penalty in general because in practice it leads to a lot of innocent but poor and black men being killed. This guy is clearly guilty, so who cares.
It is unfortunate that some governments do use the death penalty to mete out state-sponsored revenge. I think it is that usage that it has the significantly disparate impact on certain groups - particularly seen in the impact on the black population. I don't think it has to be that way.
The Declaration of Independence declares that the unalienable rights are those of life, liberty, and pursuit of happiness. The Bill of Rights reserves due process to life, liberty, and property. What I see in these lines is a natural hierarchy of justice. For the least crimes the state punishes an individual by denying pursuit of happiness or property in the form of a fine. For more severe crimes the state denies the right to liberty by imprisonment. The natural sequence of this hierarchy for the state to punish the worst of all crimes by denying the right to life.
There's no question that as it has been applied many wrongfully convicted people have been sentenced to death. The error rate is small, but nonzero, and in looking at the cases the error is typically associated with a single, highly emotional crime. I suggest the application of the death penalty for this type of crime is consistent with the claim of its use for revenge - to assuage the public when emotions are running high.
However, the researched cases of wrongful death penalties do not involve homicides from two separate killings well separated in time. The error rate becomes negligible, and that is why I suggest the two separate killings rule is a good way to identify the most severe of crimes where justice can be consistent with the denial of the right to life. That does not mean that all multiple murderers of this sort should be put to death, but just that justice may consider the death penalty in only those cases.