Strickland v. Washington

Holding an "error by counsel" doesn't "warrant setting aside the judgment of a criminal proceeding" where in the context of the whole proceeding the identified error "had no effect on the judgment"

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”

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

Lindh v. Murphy

Holding that the statutory language must be "so clear that it [can] sustain only one interpretation" favoring retroactivity

Brecht v. Abrahamson

Holding that when a court has "never squarely addressed the issue, and ha at most assumed" something in a prior decision, it is "free to address the issue on the merits"

Miranda v. Arizona

Holding that statements obtained by custodial interrogation of a criminal defendant without warning of constitutional rights are inadmissible under the Fifth Amendment

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"

Kyles v. Whitley

Holding the State's disclosure obligation turns on the cumulative effect of all suppressed evidence favorable to the defense

Section 352 - Balancing of probative value with prejudice

Giving a trial court discretion to exclude evidence "if its probative value is substantially outweighed by the probability that its admission will necessitate undue consumption of time or (b) create substantial danger of undue prejudice, of confusing the issues, or of misleading the jury"

Section 189 - Murder of the first degree

Providing that malice may be express or implied – with implied malice being, e.g. , "when the circumstances attending the killing show an abandoned and malignant heart"

Section 1101 - Evidence of character to prove conduct

Regarding admissibility of character evidence

Section 190.2 - Penalty for defendant found guilty of first-degree murder with special circumstance

Prescribing penalty of death or LWOP for special circumstance murder

Section 801 - Expert witness opinion testimony

Limiting expert testimony to opinions related to a subject that is sufficiently beyond common experience that the opinion would assist the trier of fact, and based on matter including special knowledge that is of a type that reasonably may be relied upon by an expert in forming an opinion

Section 190 - Punishment

Concerning homicide

Section 1239 - Appeal in manner provided in rules; automatic appeal of judgment of death

Section 1150 - Inquiry as to validity of verdict

Addressing admissibility of statements made, conduct, conditions, or events "likely to have influenced the verdict improperly" to challenge validity of verdict

Section 190.3 - Death penalty for defendant found guilty of first degree murder with special circumstance

Providing that, "[i]n determining the penalty, the trier of fact shall take into account" any relevant listed factors

Section 1367 - Mental incompetence of defendant

Regarding competency determination

Rule 2.893 - Appointment of interpreters in court proceedings