Williams v. Taylor

Holding that counsel's performance was deficient when their investigation failed to uncover "extensive records" filled with mitigation evidence concerning the defendant's family history, education, mental health, and rehabilitation

Apprendi v. New Jersey

Holding that “[o]ther than the fact of a prior conviction, any fact that increases the penalty for a crime beyond the prescribed statutory maximum must be submitted to a jury, and proved beyond a reasonable doubt”

Crawford v. Washington

Holding that the Sixth Amendment's Confrontation Clause bars "admission of testimonial statements of a witness who did not appear at trial unless he was unavailable to testify, and the defendant had had a prior opportunity for cross-examination"

Blakely v. Washington

Holding that “[w]hen a judge inflicts punishment that the jury's verdict alone does not allow, the jury has not found all the facts ‘which the law makes essential to the punishment,’ and the judge exceeds his proper authority”

Estelle v. McGuire

Holding that a federal habeas court may not reexamine state court determinations of state law questions

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

Tennard v. Dretke

Holding that petitioner was entitled to a COA on his Penry claim where his evidence of low IQ and impaired intellectual functioning had "mitigating dimension beyond the impact it has on the individual's ability to act deliberately"

Davis v. Washington

Holding that statements made "in the course of police interrogation" are testimonial when made under "circumstances objectively indicat[ing] ... that the primary purpose of the interrogation [was] to establish or prove past events potentially relevant to later criminal prosecution"

Cunningham v. California

Holding that the "jury-trial guarantee proscribes a sentencing scheme that allows a judge to impose a sentence above the statutory maximum based on a fact, other than a prior conviction, not found by the jury or admitted by the defendant"

Ring v. Arizona

Holding that “[i]f a State makes an increase in a defendant's authorized punishment contingent on the finding of a fact, that fact—no matter how the State labels it—must be found by a jury beyond a reasonable doubt”

Rule 703 - Bases of an Expert's Opinion Testimony

Explaining that facts or data of a type upon which experts in the field would reasonably rely in forming an opinion need not be admissible in order for the expert's opinion based on the facts and data to be admitted

Rule 609 - Impeachment by Evidence of a Criminal Conviction

Adopting a ten-year time limit, absent unusual circumstances, on the use of prior convictions for impeachment purposes

Section 8 - Powers of Congress

Granting Congress the power to “provide for the common Defence,” to “regulate Commerce with foreign Nations,” and to “establish an uniform Rule of Naturalization”

Section 15

Affording “the right ... to compel attendance of witnesses in the defendant's behalf”

Section 10 - Powers Denied to the States

Prohibiting specific acts by the States

Section 28

Granting crime victims the right "[t]o reasonable notice of all public proceedings, including delinquency proceedings, upon request, at which the defendant and the prosecutor are entitled to be present"

Section 16

Stating that the right to a "trial by jury is an inviolate right"

Section 17

Prohibiting cruel or unusual punishment

Section 9

Section 1387.1 - Refiling charges where prior dismissals due solely to excusable neglect

Permitting an additional dismissal and refiling for violent felonies

Rule 4.421 - Circumstances in aggravation