In the case of Richard Boyde v. California, the U.S. Supreme Court ruled in 1989 that jury instructions given during a capital sentencing hearing did not violate the Eighth Amendment's prohibition against cruel and unusual punishment. The petitioner, Richard Boyde, had been convicted of first-degree murder and robbery in California state court and was sentenced to death. He argued that his constitutional rights were violated because jurors may have interpreted their instructions as prohibiting consideration of certain mitigating evidence when deciding whether to impose a death sentence or life imprisonment without parole. The Supreme Court disagreed with Boyde’s argument by stating that there is no reasonable likelihood that jurors would interpret these instructions as preventing them from considering any type of mitigating evidence presented by the defense team. Therefore, it concluded that these standard jury instructions used in California do not violate an individual's right under the Eighth Amendment to present all relevant mitigating information at a capital sentencing proceeding.

In the dissenting opinion for Richard Boyde v. California, Justice Brennan, joined by Justices Marshall and Stevens, argued that the jury instructions given in this case were constitutionally inadequate because they did not clearly inform jurors of their responsibility to consider all relevant mitigating evidence before deciding on a death sentence. The majority's standard - whether there is a "reasonable likelihood" that jurors interpreted instructions in a way that prevented consideration of mitigation - was seen as too lenient by the dissenters. They believed it should be enough if there is simply a "reasonable possibility" such an interpretation occurred. Furthermore, they disagreed with the majority's view that context could clarify ambiguous instructions; instead arguing ambiguity itself was problematic due to potential variance in juror understanding and interpretation. In essence, they contended any instruction leaving room for misinterpretation about considering mitigating factors fails constitutional muster under Eighth Amendment protections against cruel and unusual punishment.