Wiggins v. Smith

Holding that counsel's performance was deficient when they failed to expand their investigation into the defendant's life history "after having acquired only rudimentary knowledge of his history from a narrow set of sources," especially when those sources indicated the existence of helpful mitigation evidence

Roper v. Simmons

Holding "that the death penalty cannot be imposed upon juvenile offenders"

Atkins v. Virginia

Holding that it violates the Eighth Amendment to execute intellectually disabled defendants

Arizona v. Fulminante

Holding that involuntary confessions are subject to harmless-error review

Bracy v. Gramley

Holding that "the Due Process Clause of the Fourteenth Amendment establishes a constitutional floor, not a uniform standard" and noting the existence of many laws that legislate above that constitutional minimum

Wainwright v. Witt

Holding that juror bias determination is a question of fact, even though "[t]he trial judge is of course applying some kind of legal standard to what he sees and hears"

Furman v. Georgia

Holding that death penalty cannot be imposed using sentencing procedures that create a risk of arbitrary and discriminatory enforcement

Eddings v. Oklahoma

Holding that a sentencing court cannot "refuse to consider, as a matter of law , any relevant mitigating evidence"

Simmons v. South Carolina

Holding that when the state raised the specter of a defendant's future dangerousness, the court violated his due process rights by refusing to instruct the jury that, as an alternative to a capital sentence, the sentence of life imprisonment included absolutely no possibility of parole

Irvin v. Dowd

Holding that eight jurors’ predisposed opinions as to guilt based on adverse pre-trial publicity violated the defendant's right to an impartial jury

Rule 8.630 - Briefs by parties and amicus curiae