The 14th Amendment guarantees equal protection and due process for all. The death penalty is a sick joke on the Constitution. There is no credible evidence that executions deter crime. Crime correlates far better to population density, wealth inequity, and the concentration of young males than to law enforcement factors. Capital punishment also costs two or three times more than life without parole.
Few defendants plead guilty to a capital charge, so most every capital trial becomes a jury trial.
We're wasting tens of millions of dollars. Allowed to live, inmates can be put to work, with the proceeds benefitting the victim's family. Besides, if the accused is later exonerated, the jail door can open. You can't raise the dead. The Eighth Amendment prohibits cruel and unusual punishment.