Case Law

The term case law refers to law that comes from decisions made by judges in previous cases. Case law, also known as “common law,” and “case precedent,” provides a common contextual background for certain legal concepts, and how they are applied in certain types of case. How much sway case law holds may vary by jurisdiction, and by the exact circumstances of the current case.  To explore this concept, consider the following case law definition.

Definition of Case Law


  1. The law as established in previous court rulings; like common law, which springs from judicial decisions and tradition.


1860-1865       English common law

What is Case Law

Statutory laws are those created by legislative bodies, such as Congress at both the federal and state levels. While this type of law strives to shape our society, providing rules and guidelines, it would be impossible for any legislative body to anticipate all situations and legal issues. The court system is then tasked with interpreting the law when it is unclear how it applies to any given situation, often rendering judgments based on the intent of lawmakers and the circumstances of the case at hand. Such decisions become a guide for future similar cases.

In order to preserve a uniform enforcement of the laws, the legal system adheres to the doctrine of stare decisis, which is Latin for “stand by decided matters.”  This means that a court will be bound to rule in accordance with a previously made ruling on the same type of case. Precedent, or case law, is binding on courts of the same level or lower, and applies only if there is no legislative statute created, or higher court ruling, that overrules it.

Example of Case Law Application

Stacy, a tenant in a duplex owned by Martin, filed a civil lawsuit against her landlord, claiming he had not given her enough notice before raising her rent, citing a new state law that requires a minimum of 90 days’ notice. Martin argues that the new law applies only to landlords of large multi-tenant properties. When the state court hearing the case reviews the law, he finds that, while it mentions large multi-tenant properties in some context, it is actually quite vague about whether the 90-day provision applies to all landlords. The judge, based on the specific circumstances of Stacy’s case, decides that all landlords are held to the 90-day notice requirement, and rules in Stacy’s favor.

A year later, Frank and Adel have a similar problem. When they sue their landlord, the court must use the previous court’s decision in applying the law. This example of case law refers to two cases heard in the state court, at the same level. The ruling of the first court created case law that must be followed by other courts until or unless either new law is created, or a higher court rules differently.

Case Law by Jurisdiction

Case law is specific to the jurisdiction in which it was rendered. For instance, a ruling in a California appellate court would not usually be used in deciding a case in Oklahoma. While there is no prohibition against referring to case law from a state other than the state in which the case is being heard, it holds little sway. Still, if there is no precedent in the home state, relevant case law from another state may be considered by the court.

Rulings made by federal appellate courts, and the U.S. Supreme Court, however, are binding on state courts. Such rulings become “binding precedent,” which must be adhered to by lower courts in future similar cases. Rulings by courts of “lateral jurisdiction” are not binding, but may be used as persuasive authority, which is to give substance to the party’s argument, or to guide the present court.

Case Law Search

Just a few years ago, searching for case precedent was a difficult and time consuming task, requiring people to search through print copies of case law, or to pay for access to commercial online databases. Today, the internet has opened up a host of case law search possibilities, and many sources offer free access to case law. Doing a case law search may be as easy as entering specific keywords or citation into a search engine. There are, however, certain websites that facilitate case law searches, including:

  • Google Scholar – a vast database of state and federal case law, which is searchable by keyword, phrase, or citations. Google Scholar also allows searchers to specify which level of court cases to search, from federal, to specific states.
  • Justia – a comprehensive resource for federal and state statutory laws, as well as case law at both the federal and state levels.
  • Public Library of Law – offers access to cases from the U.S. Supreme court since 1754, the U.S. Circuit Courts of Appeal since 1951, and from each state since 1997. In addition to allowing users to search by keyword, court, and case, the website provides tutorials on “Finding a Case,” and “Searching Statutes.”

In addition, the Law Library of Congress offers a great deal of information on statutes, case law, and other legal issues. This includes a Guide to Law Online.

Dissecting Case Law Citations

Finding a relevant case law ruling, and inserting a reference to that case into a current legal pleading, is not enough to direct the court to the specific issue. In many instances, court rulings in the U.S. deal with multiple issues, and include drawn-out descriptions of how the court, especially an appellate or supreme court, came to its conclusion. Because of this, simply citing the case is more likely to annoy a judge than help the party’s case. Think of it as calling someone to tell them you’ve found their lost phone, then telling them you live in such-and-such neighborhood, without actually giving them an address. Driving around the neighborhood trying to find their phone is likely to be more frustrating than it’s worth.

For legal professionals, there are specific rules regarding case citation, which vary depending on the court and jurisdiction hearing the case. Proper case law citation in a state court may not be appropriate, or even accepted, at the U.S. Supreme Court. Generally speaking, proper case citation includes the names of the parties to the original case, the court in which the case was heard, the date it was decided, and the book in which it is recorded. Different citation requirements may include italicized or underlined text, and certain specific abbreviations.

In the United States, people are not required to hire an attorney to represent them in either civil or criminal matters. Laypeople navigating the legal system on their own can remember one rule of thumb when it comes to referring to case law or precedent in court documents: be as specific as possible, leading the court, not only to the case, but to the section and paragraph containing the pertinent information. The Cornell Law School website offers a variety of information on legal topics, including citation of case law, and even provides a video tutorial on case citation.

Case Law Example in Civil Lawsuit Against Child Services

In 1996, the Nevada Division of Child and Family Services (“DCFS”) removed a 12-year old boy from his home to protect him from the horrible physical and sexual abuse he had suffered in his home, and to prevent him from abusing other children in the home. The boy was placed in an emergency foster home, and was later shifted around within the foster care system. The DCFS social worker in charge of the boy’s case had the boy made a ward of DCFS, and in her 6-month report to the court, the worker elaborated on the boy’s sexual abuse history, and stated that she planned to move him from a facility into a “more homelike setting.” The court approved her plan.

In 1997, the boy was placed into the home of John and Jane Roe as a foster child. Although the couple had two young children of their own at home, the social worker did not tell them about the boy’s history of both being abused, and abusing other children. When she made her report to the court the following day, the worker reported the boy’s placement in the Roe’s home, but didn’t mention that the couple had young children. She did note that the boy still needed extensive therapy in order to cope with his abusive past, and “to reach the point of being safe with other children.” The boy was receiving counseling with a DCFS therapist. Again, the court approved of the actions.

The Roes accompanied the boy to his therapy sessions. When they were told of the boy’s past, they asked if their children were safe with him in their home. The therapist assured them that they had nothing to worry about. Unfortunately, that was not true. Just two months after being placed with the Roe family, the Roe’s son told his parents that the boy had molested him. The boy was arrested two days later, and admitted to having sexually molested the couple’s son several times.

On June 16, 1999, a lawsuit was filed on behalf of the boy by a guardian ad litem, against DCFS, the social worker, and the therapist. A similar lawsuit was also filed on behalf of the Roe’s victimized son by a different guardian ad litem. The defendants petitioned the trial court for a dismissal based on absolute immunity, as they were all acting in their jobs with DCFS. If granted absolute immunity, the parties would not only be protected from liability in the matter, but could not be answerable in any way for their actions. When the court delayed making such a ruling, the defendants took their request to the appellate court.

In determining whether employees of DCFS are entitled to absolute immunity, which is generally held by certain government officials acting within the scope of their employment, the appellate court referred to case law previously rendered on similar cases. The appellate court determined that the trial court had not erred in its decision to allow more time for information to be gathered by the parties – specifically regarding the issue of absolute immunity.

Related Legal Terms and Issues

  • Binding Precedent – A rule or principle established by a court, which other courts are obligated to follow.
  • Lateral Jurisdiction – A court at the same level.
  • Persuasive Authority – Prior court rulings that may be consulted in deciding a current case. It may be used to guide the court, but is not binding precedent.