In 1960, a Cook County jury found William C. Witherspoon guilty of the murder of a Chicago police officer, and he was sentenced to death.

[2] The others were excluded for indicating "conscientious scruples" of varying degrees against the death penalty, of whom only one was asked any subsequent questions about the exact nature of her views.

While they rejected the petitioner's argument that jurors who actively support the death penalty are necessarily biased towards the prosecution, they held that the Illinois statute created an unconstitutional bias towards capital punishment and deprived Witherspoon of due process.

[2][3] Writing for the majority, Justice Potter Stewart wrote: Whatever else might be said of capital punishment, it is at least clear that its imposition by a hanging jury cannot be squared with the Constitution.

The decision would become national in scale when the U.S. Supreme Court also in 1972 ruled in Furman v. Georgia that all death penalty cases were in violation of the 8th Amendment's prohibition on cruel and unusual punishment.