Legal research is the process of identifying and retrieving information to support legal arguments and decisions. Finding relevant legal information can be challenging and may involve the use of electronic research tools as well as printed books and materials. However, many resources that are useful for legal research are fee-based, and many are not easily accessible.
Primary sources
Primary sources of law are the original sources of the law. Such sources include statutes, government regulations, case law and the text of the state and federal constitutions.
Judicial branch sources (Cases)
The Judicial branch is the court system. Each jurisdiction in the U.S. judiciary (federal and the fifty states) has any number of courts, usually one of three types: a trial court, an appeals court, a "court of last resort," often (but not always) known as a Supreme Court.
At the federal level, there is a Supreme Court of the United States, United States court of appeals, and a trial court, which is known as the United States district court. The federal appellate courts are subdivided into numbered "circuits." Pennsylvania, for example, is in the jurisdiction of the Third Circuit Court of Appeals.
In general, the decisions of a higher court in a court system may be considered "binding" on the lower courts in that court system. The decisions of the Supreme court of a particular state are binding on the courts within that state. However, the decisions of a Pennsylvania state court may or may not be followed by a federal court in the Third Circuit, which includes Pennsylvania. The status of United States Supreme court opinions is complex, but U.S. Supreme Court decisions are final on both federal disputes and federal issues raised in state courts.
Only a small percentage of court decisions are officially published in a print court reporter. The most published decisions are issued by the United States Supreme court. State trial courts produce the lowest percentage of published cases. Some courts provide copies of their decisions free on the web while others do not. Even if they are on the web they seldom go back before 1994, when the web first became popular. The only exception is with U.S. Supreme Court opinions.
Cases on the web can often be found via the website of the individual court. The Supreme Court of the United States, for example, provides the text of recent opinions on its website. It is one of the best places to obtain new opinions. The United States court of appeals and State courts can also be a source of free legal information.
In print, to find the cases, legal researchers use indexes of various types. Classification systems provide index terms. For example, there may be a category of law, torts (non-crime injuries to people). There are many types of torts, or causes of Action, such as slander. These causes of actions have various elements which must be proved to establish a claim (there may also be various defenses). The general category, the cause of action and the various elements of the cause of action and defenses may all be index terms. The major classification for finding law cases is the West American Digest System.
The key to using legal indexes is to identify not only the key facts but the legal issues which are central to the case. Keyword searches in databases may also be a challenge, because people may describe legal concepts in varying ways. "Issue spotting" is a skill that lawyers home in law school and throughout their careers as they gain experience. For the layperson, reading secondary sources, such as books and journal articles, can help.
Once a case has been found, legal researchers must make sure that it has not been overturned by a higher court. Lawyers use citators such as Shepard's Citations to make sure that their case is still "good law." This process is often known as Shepardizing after the name of the service. Citators track resources, written at a later point in time, which cite back to a particular case. Because cases cite to related cases, citators can be used to find cases which are on the same topic. A common research strategy is to use "one good case" to find related cases.
Legal forms can be some of the hardest documents to find because one person may call a form by one name while another person knows it by an entirely different name (neither of which may be the actual, official name of the form). The same form may be known by a different name in a different jurisdiction. Law libraries often have many sets of formbooks to search.