When looking for case law, many times you will be able to start with the citation of a case. If you have this information, you can typically find the full text of the opinion by entering the citation into an appropriate database. If you do not have a citation, but know the subject which you'd like to search, use a tool or database that supports full-text searching. The more detail you use, the more likely you will find a case on point (if one exists); less detail will provide more, but possibly irrelevant, results. Perform a number of searches using different combinations of terms, and synonyms for terms, to ensure the best results.

When you have found a case that seems relevant, always check to see if the case is still good law. Many subscription resources, such as Hein Online, have an online tool to check for you. Read any relevant citations in the case you have found as an aid in finding additional resources. Similarly, search on the case you've found to find later references and more current case law.

Some cases may have headnotes or annotations. They may summarize the case or its holding, but are not part of the official decision and should only be relied upon for clarification. Citations should always be to the body of the case. Some headnotes are used by publishers to provide an indexing system that allows you to find cases on the same topic. Case digests can be used to find these cases.

ASU Sandra Day O'Connor College of Law

Other legal research databases are available remotely to students and faculty of the ASU Sandra Day O'Connor College of Law or are available to all patrons in person at the Ross-Blakley Law Library at the ASU Sandra Day O'Connor College of Law.

Case law operates under the principle of stare decisis, which requires lower courts to follow the opinions of courts above them. Knowing the hierarchy of courts will allow you to assess the strength of the opinions you've found.

Arizona

In Arizona, the highest court is the Arizona Supreme Court. Below it you will find the Arizona Court of Appeal. Arizona also has lower courts of general or limited jurisdiction which include Superior Courts, Magistrate (City or Municipal) Courts, and Justice of the Peace Courts.

Federal Courts

The Federal Courts are organized similarly with a Supreme Court, Courts of Appeal, and District Courts. Unlike Arizona, the Courts of Appeal are divided into 13 divisions, most of which are geographically divided, with other assigned specific functions and type of cases. In the federal system, the Supreme Court determines precedent for all of the circuits of the Courts of Appeal, but one Court of Appeal is not mandatory authority for another. For example, Arizona is in the Ninth Circuit Court of Appeal, and a decision in Colorado by the Tenth Circuit would not be binding on Arizona courts.