According to the Supreme Court, a constitutional capital sentencing scheme must provide a way to “genuinely narrow” the class of those eligible for the death penalty and must “reasonably justify” imposing a more severe sentence compared to others found guilty of murder. This stems from the Court’s decision in Furman v. Georgia that a death sentence was unconstitutional when it was applied only to “a capriciously selected random handful upon whom the sentence of death has in fact been imposed.” Death sentences are to be reserved for the “worst of the worst” offenders (i.e. only those most deserving of execution). States are therefore required to define death-eligible crimes in a way that avoids “standardless [sentencing] discretion.” In order to keep their capital sentencing schemes constitutional, states have adopted systems of “aggravating” and “mitigating” factors which are designed to ensure that death sentences are actually imposed on only the most deserving of offenders. “This means that if a State wishes to authorize capital punishment it has a constitutional responsibility to tailor and apply its law in a manner that avoids the arbitrary and capricious infliction of the death penalty.”
"Can All Murders Be “Aggravated?” A Look at Aggravating Factor Capital-Eligibility Schemes,"
Saint Louis University Law Journal: Vol. 63
, Article 8.
Available at: https://scholarship.law.slu.edu/lj/vol63/iss4/8