You may hear this referred to as a "case in hand" or "one good case" searching method. What this refers to is using an on point case that you have already found to find other relevant cases on your issue by using that case's headnotes.
Headnotes: Headnotes are very short entries on legal issues that are found at the beginning of a case. From a headnote you can click on a West Key Number, or a Lexis Topic Document or Topic Index link to find additional cases.
Annotated statutes contain references to other materials related to that particular statute, including case annotations. Case annotations are editorially selected summaries of cases that are illustrative of how a particular statute has been applied by the courts.
Finding Case Annotations
Cases in both are divided by topic to help you find the cases most relevant to your issue.
Annotated Statutes are not available in Bloomberg Law.
Westlaw: In the Browse box, click the Tools tab and select the West Key Number System. From here you can search the West Key Number System from the search bar at the top or browse the list of 450 topics. If you click through to a digest document (a listing of cases that fall under a specific topic and key number), you select a different jurisdiction at the top of the screen and search within that listing.
Lexis Advance: Click the Browse Topics option at the top of the Lexis Advance home page. You will see the topic index for Lexis Advance; you can either search with the search box provided or browse through the list of top-level topics which are further divided into sub-topics. You can add topics to a search or view the Topic Documents (See "Finding Cases using Headnotes").
Secondary sources, such as legal encyclopedias or the American Law Reports, are great places to start your research and can help you find relevant case law on your topic.
Legal Encyclopedias: Legal encyclopedias are similar to encyclopedias that you may have used as an undergraduate, except that they focus on brief overviews of legal topics. Different encyclopedias will have different features, but keeping an eye out for the following will help you locate additional case law:
American Law Reports: American Law Reports contain in-depth articles on legal topics. Each article has its own table of contents, index, and research references. You can find relevant cases by looking at the: