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Pritzker Legal Research Center


Researching Case Law

Guide to researching cases

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Why do you need to use a citator?

Legal citators are valuable tools that tell you what has happened to a law after it’s been promulgated and what primary and secondary sources have cited to the law.  KeyCite and Shepard’s are two updating systems through Westlaw and Lexis Advance that are reliable ways to update case law and make sure that the cases are still good law.

This is always the last step in the legal research process, and it is imperative for ensuring that your cases and statutes are current prior to entering the courtroom and representing a case for your client.

Shepard's (LexisAdvance)

Lexis Advance calls its legal citator a Shepard’s Report.  The Report is divided into 3 tabs:

  • Appellate History explains the evolution of this case by providing hyperlinks to previous and subsequent opinions in this case
  • Citing Decisions lists all the cases (organized by jurisdiction) that cite to our case in some capacity
  • Citing Law Reviews, Treatises, and Secondary Sources lists where this case is mentioned in secondary source or an annotated statute

Shepard's signals
A yellow triangle indicates that there may be some negative treatment but that the case has not been overturned.  The red octagon indicates that the case has been overturned on at least one point of law. 

A full list of all the signals and additional help in using Shepard's is available in the Lexis Advance Help Guide.

KeyCite (Westlaw)

Westlaw’s citator is called KeyCite.  The KeyCite Report includes the Citing References, Negative Treatment and History tabs.

  • Citing References  lists all the cases (organized by depth of treatment) that cite to our case in some capacity
  • Negative Treatment  lists only the citing cases from the Citing References tab that received negative treatment
  • History lists the related previous and subsequent opinions in this case

KeyCite Signals
Westlaw, like Lexis Advance, uses signals to indicate what kind of treatment a case has.  Westlaw uses a yellow flag as opposed to the yellow triangle that Lexis Advance uses.  

A full list of KeyCite signals is available in KeyCite on Westlaw guide (pdf).

BCite (Bloomberg Law)

Bloomberg Law's citator is called BCite.  This citator includes:

  • Direct History lists the related previous and subsequent opinions in this case
  • Citation Analysis lists all the cases (organized by date - most recent first) that cite to our case in some capacity
  • Table of Authorities lists the cases cited in this case

BCite Symbols
BCite includes symbols that denote Positive, Distinguished, Caution, Superseded by Statute, and Negative references.

Read the cases!

Don’t rely on the signal alone!

A red signal doesn’t necessarily mean it’s bad law.  It might be that the case was distinguished or overturned because of one point or legal issue within the legal opinion, but not necessarily the legal issue that you are researching.  

It is critical that you spend the time reading the context of your subsequent citing decision.