Furman v. Georgia, 408 U.S. 238 (1972), was a landmark criminal case in which the United States Supreme Court decided that arbitrary and inconsistent imposition of the death penalty violates the Eighth and Fourteenth Amendments, and constitutes cruel and unusual punishment.

Most states at that time did not allow the presentation of mitigating and aggravating evidence that today is a constitutionally required part of individualized consideration at sentencing.

[3] In McGautha v. California, decided thirteen months before Furman, the Court held that due process did not require instructions to the jury about standards to guide sentencing in capital cases.

[8] The Court's one-paragraph per curiam opinion held that "the imposition of the death penalty...in these cases constitute cruel and unusual punishment in violation of the Eighth and Fourteenth Amendments.

The median justices Potter Stewart and Byron White were concerned that erratic and arbitrary imposition of the death penalty violated the constitutional prohibition against cruel and unusual punishment.

[11] Justice Douglas said :[4] It would seem to be incontestible that the death penalty inflicted on one defendant is 'unusual' if it discriminates against him by reason of his race, religion, wealth, social position, or class, or if it is imposed under such a procedure that gives room for the play of such prejudices.

Justices William J. Brennan and Thurgood Marshall concluded that the death penalty was in itself "cruel and unusual punishment" because it was excessive, served no valid legislative purpose and was incompatible with the evolving standards of decency of a contemporary society.

[12] In his concurrence Justice Brennan said the low rate of jury imposed sentences, relative to number of death penalty eligible cases, indicated that sentencing outcomes were unconstitutionally arbitrary:[5][13] When the punishment of death is inflicted in a trivial number of the cases in which it is legally available, the conclusion is virtually inescapable that it is being inflicted arbitrarily ...When the rate of infliction is at this low level, it is highly implausible that only the worst criminals or the criminals who commit the worst crime are selected for this punishment.Justice Marshall said Americans "know almost nothing about capital punishment" and would not "knowingly support purposeless vengeance".

[19] Many of the new statutes that mandated bifurcated trials, with separate guilt-innocence and sentencing phases, and imposed standards guiding juries and judges during the penalty phase, were upheld in a series of Supreme Court decisions in 1976, beginning with Gregg v. Georgia where the Court said that "a carefully drafted statute that ensures that the sentencing authority is given adequate information and guidance" would meet the constitutional standard of Furman.

[13] Other statutes enacted in response to Furman, such as Louisiana's, which mandated imposition of the death penalty upon conviction of certain crimes, were invalidated for cases of that same year.