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Effective Case Law Research

Effective and efficient case law research is essential to the success of many summer associates, particularly those involved in litigation. This Guide briefly explains effective techniques for quickly and thoroughly identifying key cases addressing the legal issue you are researching.

Many law firms will expect you to do most, if not all, of your case law research online. This Guide focuses on online methods using Westlaw and Lexis. For information on using free online sources, click here. For information on using print sources, click here. Be sure you know your firm's limitations and recommendations for online research.

There are important points of information you should be sure you know before you start your research. At the time you receive your assignment, think of the acronym JUST ASK to remind you to ask the assigning attorney about jurisdiction and other key details.

I. Starting your case research when you have leads

  1. Read any cases that your assigning attorney suggests.
  2. If you are responding to a motion or brief, read and update the cases and other authorities opposing counsel cites. You will learn more about the issues and you may find that some cases have not been used correctly. This work could include reviewing briefs submitted in some of those cases that your opposing counsel cites. For information regarding what courts have their briefs available online through Westlaw or Lexis, as well as free web sites, click here.

II. Starting your case research when you have no leads

  1. If you are unfamiliar with an area of law, starting your research by reading something general about the topic in a secondary source is worthwhile. It will save you time (and time equals your client’s money!) in the long run and may help answer other preliminary questions you may have.
  2. Look first for a statute. If there is a statutory provision addressing your topic of law, it is the starting point for your research. (Click here to learn about the importance of a statute in your legal research.) You should never assume the absence of a relevant statute. Annotated versions of statutes will provide references to cases interpreting the statute. For more information on annotated codes, click here.
  3. Always search the smallest database possible. There are very few times you will need to search for cases from every state or federal circuit, or even from any state or federal circuit other than your own. A quick look at the Westlaw Directory of Databases or the Lexis Directory of Online Services in print can help you choose the best database before you go online.
  4. Analyze the facts you have been given and generate a list of search terms. Think of possible synonyms or alternative ways of expressing the terms. Consider using a field or segment search, such as one requiring your terms to appear in the synopsis and headnotes, which succinctly describe the case.
  5. A natural language search may quickly identify a few key cases on point. You should never rely solely on natural language searches to retrieve all of the relevant cases, but they can be useful to help you form effective terms and connectors searches.

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III. Techniques for thorough retrieval of relevant cases

Once you have identified one or more cases on point, use a combination of the following techniques to expand your research.

  1. Shepardize and/or Key Cite each case you expect to use to support your argument. If you do this as soon as you read a key case, not only will you validate right away that your case is still good law, but you will also find any cases that have cited your case and may have developed the point of law. For more information on how to use Shepard's and Key Cite to retrieve more relevant cases, click here.
  2. Working from a good case, use relevant West topic and key numbers or Lexis core concepts to find additional cases on point. (For an overview on the topic and key number system, click here.) Once you have found a relevant topic and key number on Westlaw, you can use the “Most Cited Cases” function to retrieve a list of the cases most often cited for that proposition. (Click here for help on finding the appropriate topic and key number.) For information on how to use this function of Westlaw, click here. On Lexis, “More Like This Headnote” essentially serves the same function. Both services permit you to choose the jurisdiction from which you want the additional cases to come.
  3. Not every point of law has been decided in every jurisdiction. If you don’t find relevant authority in your jurisdiction, consider searching for relevant cases from other jurisdictions. Although outside case law will not be binding on the courts of your jurisdiction, well-reasoned cases from other courts on closely analogous facts can be good persuasive authority and good support for your arguments.
  4. Know when to stop. If the cases you are finding are all starting cite to each other, it is a good bet that your research has come full circle.
  5. Update your cases just before handing in a memo or filing a brief. You can either update them manually or use either KeyCite Alert on Westlaw or Shepard's Alert on Lexis.

    Notes to Remember:

  1. Unpublished opinions may not be acceptable authority in your jurisdiction – check your local rules.
  2. If you have more questions during your legal research, talk to your law firm’s librarian or with the reference staff of the Harvard Law School Library by email or by phone at 617-495-4516. Westlaw and Lexis also maintain help lines that can help you with constructing effective searches and provide detailed information on their databases.