Stare decisis

Stare decisis is the doctrine of precedent, or that a court decides things based on how previous courts have decided things. It's also called the Auto Equity Sales doctrine. It sounds simple in theory. If a rule is stated in a published case and it hasn't been overruled by a later case, then that rule should be followed. However, how that actually works out is a lot more complicated.

Auto Equity Sales, Inc. v. Superior Court (1962) 57 Cal.2d 450, 455, stated the principle of stare decisis: “Under the doctrine of stare decisis, all tribunals exercising inferior jurisdiction are required to follow decisions of courts exercising superior jurisdiction.... Courts exercising inferior jurisdiction must accept the law declared by courts of superior jurisdiction. It is not their function to attempt to overrule decisions of a higher court.”

Decisions of the Supreme Court of the United States

Decisions by the Supreme Court of the United States on issues of federal law are binding on all California courts. (People v. Superior Court (Williams) (1992) 8 Cal.App.4th 688, 702–703; People v. Bradley (1969) 1 Cal.3d 80, 86;

Decisions of the Supreme Court of California or Court of Appeal of California

Courts are not bound by decisions of the California Supreme Court, where the United States Supreme Court has ruled to the contrary. (People v. Greenwood (1986) 182 Cal.App.3d 729, 734, revd. on other grounds in California v. Greenwood (1988) 486 U.S. 35; People v. Rooney (1985) 175 Cal.App.3d 634, 644.

Courts are not bound by dicta in California Supreme Court opinions. (State of California v. Superior Court (2000) 78 Cal. App.4th 1019, 1029) "When the Supreme Court has conducted a thorough analysis of the issues and such analysis reflects compelling logic, its dictum should be followed." (Hubbard v. Superior Court (1997) 66 Cal.App.4th 1163, 1169.)

Decisions of the Appellate Division or Appellate Department of the Superior Court

Before court unification by Prop 220 in 1998, the trial courts in California were the Municipal Courts and the Superior Courts. The Appellate Department of the Superior Court heard appeals from the Municipal Court. Prop 220 merged the Municipal Courts into the Superior Courts and replaced the Appellate Department with the Appellate Division.

The precedent of an Appellate Division decision is different from that of the Supreme Court or Court of Appeal. An Appellate Division decision is binding on the Superior Court of that county. (See People v. Love (1980) 111 Cal.App.3d Supp. 1, 13. ("This decision, as are all published and final opinions of this appellate department of the Los Angeles Superior Court, is binding on all municipal courts located within the County of Los Angeles.")) However, an Appellate Division decision is only persuasive authority, not mandatory authority, for the Superior Court of another county. (People v. Conzelman (1994) 33 Cal.App.4th Supp. 6, 10 ("An opinion from the Appellate Department of the Ventura Superior Court is not binding in Orange County."); People v. Corners (1985) 176 Cal.App.3d 139, 146 ("[A] decision of the Appellate Department of the San Francisco Superior Court is not binding upon the Butte County Superior Court nor upon this court."))

Decisions of federal courts or courts of other states

Decisions of federal courts other than the Supreme Court are not binding, even on federal law. However, they are persuasive and entitled to great weight. (People v. Bradley (1969) 1 Cal.3d 80, 86)

Unpublished decisions

California Rules of Court Rule 8.115 (former Rule 977) is pretty clear. "[A]n opinion of a California Court of Appeal or superior court appellate division that is not certified for publication or ordered published must not be cited or relied on by a court or a party in any other action." The exceptions are for law of the case, res judicata, or collateral estoppel, or when it states reasons for a decision affecting the same defendant or respondent.

Effect of decisions on pending or not yet final cases

In situations involving pending cases or cases that are not yet finals, when the Supreme Court of the United States announces a new rule in federal constitutional law, "a new rule for the conduct of criminal prosecutions is to be applied retroactively to all cases". (Griffith v. Kentucky (1987) 479 U.S. 314, overruling Stovall v. Denno (1967) 388 U.S. 293; accord People v. Reyes (1998) 19 Cal.4th 743, 755 ["all new constitutional rules of criminal procedure are fully retroactive to cases not yet final, even when they represent a `clear break' with the past"]; People v. Davis (1997) 57 Cal.App.4th 1404, 1408, fn. 6.) However, the Griffith rule does not apply to matters of state law. (People v. Murtishaw (1989) 48 Cal.3d 1001, 1013; People v. Carrera (1989) 49 Cal.3d 291.) Instead, in matters of state laws, courts first determine if case that is being retroactively applied is a "clear break with the past." A clear break with the past is when "when the decision (1) explicitly overrules a precedent of [the California Supreme Court] [citation], or (2) disapproves a practice impliedly sanctioned by prior decisions of [the California Supreme Court], or (3) disapproves a longstanding and widespread practice expressly approved by a near-unanimous body of lower-court authorities." (People v. Guerra (1984) 37 Cal.3d 385, 401-402.) If it's a clear break with the past, courts then apply the three-part test elucidated in Stovall, In re Johnson (1970) 3 Cal.3d 404, and Donaldson v. Superior Court (1983) 35 Cal.3d 24, 38: "(a) the purpose to be served by the new standards, (b) the extent of the reliance by law enforcement authorities on the old standards, and (c) the effect on the administration of justice of a retroactive application of the new standards." (Stovall v. Denno (1967) 388 U.S. 293, 297.) The first part, the purpose of the new rule, is the most important. If it goes towards finding guilt or innocence, then it is automatically retroactive. (Guerra, at pp. 401-402.) However, if it's a non-fact-finding purpose, like the exclusionary rule's goal to ensure proper police behavior, then it's not retroactive. (People v. Stanley (1995) 10 Cal.4th 764; Donaldson, at p. 39.)