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 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.

Lexis calls its legal citator a Shepard’s Report. A Shepard's Report includes the following tabs:

• Citing Decisions: lists all the cases (organized by jurisdiction) that cite to our case in some capacity
• History: shows the evolution of this case by providing hyperlinks to prior and subsequent opinions in this case
• Other Citing Sources: lists where this case is mentioned in secondary sources (e.g., law reviews, treatises) or an annotated statute

Shepard's signals indicates subsequent history and treatment of a case. For a detailed explanation on how to use Shepard's signals, please see Lexis's guide on Shepard's Signal indicators and treatments. 

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

• 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

Westlaw also uses signals to indicate case treatment.

For more information about how to use KeyCite, please see Westlaw's Student Guide to KeyCite. 

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BCite includes symbols that denote Positive, Distinguished, Caution, Superseded by Statute, and Negative references.

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.