The Judicial branch interprets the law whenever there is confusion or a conflict about its implementation or enforcement. Case law is found in the published, written opinions of judges, and it includes the judge’s decision and the reasoning behind it. Opinions are published in series called Reporters, which contain the text of opinions arranged chronologically. They are indexed in Digests, which may be broken down by topic and/or geography.
Looking for published court opinions (case law)? Start with Nexis Uni, WestlawNext, or HeinOnline.
These resources are also good for finding law review articles and codified laws and administrative codes.
Tip: Nexis Uni, Westlaw, and HeinOnline only include published court opinions, which means that lower level court cases (civil cases, trials) are not included. However, news sources can be particularly useful as primary sources that describe events as they unfold. The Library subscribe to a number of online sources for United States and international news.