Which Supreme Court case involved an armed robbery and murder where the defendant argued their sentence was "cruel and unusual"?

The case that accurately addresses the argument of "cruel and unusual punishment" in the context of an armed robbery and murder is Furman v. Georgia. In this landmark decision from 1972, the Supreme Court examined the constitutionality of the death penalty as it was applied at the time. The case arose when the defendant, Furman, committed a crime that resulted in his conviction and subsequent sentencing to death. The Court ultimately ruled that the death penalty, as administered, constituted cruel and unusual punishment under the Eighth Amendment due to its arbitrary and capricious nature.

Gregg v. Georgia later reaffirmed the constitutionality of the death penalty under a revised system with certain safeguards, but it involved different aspects of sentencing and was not centered around the argument of "cruel and unusual" in the same way as Furman. Roper v. Simmons addressed the issue of executing juvenile offenders and In re Gault focused on juvenile due process rights, neither of which are related to the specific context of armed robbery and murder. Thus, the focus on the Eighth Amendment's prohibition against cruel and unusual punishment aligns most directly with Furman v. Georgia.