Updating a case means to check to make sure it is still good law for the legal issue you are researching. A case is good law for an issue if its holding on that issue has not been reversed or overruled or superseded by a statute.
To update a case, you use a citator. Keycite® is the citator for Westlaw. Shepard's® is the citator for Lexis.
A citator warns you when a case has received negative treatment. As Westlaw puts it, there are two kinds of negative treatment:
Lexis describes the same concept slightly differently, swapping the terms negative treatment and negative citing references. On Lexis, there are two kinds of negative citing references: negative history (part of the same litigation or proceedings) and negative treatment (part of other litigation or proceedings).
For any case you plan to cite for a particular proposition, investigate until you understand why the citator assigned a particular flag or signal to that case. If a case is bad law for the proposition, you must not cite it. If a citator has brought other concerns to your attention, think through whether another case would be stronger. But if the case is good law, you can cite the case. No case is perfect; just make sure you understand what the potential concerns are.
Westlaw uses two flags to indicate negative treatment:
Westlaw Edge uses a blue striped flag to alert you that a case has been appealed to the U.S. Court of Appeals or the U.S. Supreme Court (not from federal agencies).
Lexis uses three key signal indicators to indicate negative history or treatment:
Westlaw uses a red KeyCite flag to alert you that a case is no longer good law for at least one of the points of law it contains and a yellow KeyCite flag to indicate negative treatment that is less severe.
For example, the whistleblower decision in Lawson has been assigned a red KeyCite flag because it is no longer valid for at least one point of law. In fact, the 2012 First Circuit decision was reversed and remanded by the U.S. Supreme Court in 2014. (Click the image below to enlarge.)
Click on the red flag to go to the Negative Treatment tab. The "Most Negative" case is the reason for the flag on the 2012 First Circuit Lawson decision. (Click the image below to enlarge.)
Select the History tab to view the complete history of the Lawson case in list and graphical formats. This can help you understand the procedural context of the case, chronologically and in terms of which levels of courts have been involved. (Click the image below to enlarge.)
U.S. v. Harrison shows a yellow KeyCite flag because it was distinguished by at least one court. It is still good law because it has not been reversed or overruled or superseded by statute. However, before you rely on a case as support for a point of law, you should be sure you fully understand how each case that caused a yellow flag does or does not affect the case's value as precedent.
Next to the yellow flag, Westlaw mentions the case that provides the most pause before relying on U.S. v. Harrison. However, notice that the case is from a district court in Michigan. When a district court distinguishes a Court of Appeals case (Harrison was decided by the Third Circuit Court of Appeals), that does not affect the precedential value of the Court of Appeals case. (Click the image below to enlarge.)
Click the yellow flag to go to the Negative Treatment tab and see links to all cases that contribute to the reasons for the flag. Notice that the Michigan district court case is labeled Most Negative. However, there are also two other cases. One of them is a state case from the Supreme Court of New Jersey. If you were arguing in a New Jersey state trial court or appeals court, that case would affect the precedential value of U.S. v. Harrison. However, if you are arguing anywhere else, that case would not affect the precedential value of U.S. v. Harrison.
Something else to consider when you find cases that distinguish a case you KeyCited, is whether the facts of your client's situation are more similar to the facts of the case you KeyCited or to a distinguishing case. This may cause you to skim some other cases to ensure that you've identified the case that is most on point.
You may be citing one particular proposition from U.S. v. Harrison, the statement about losing a right to privacy in abandoned property, which Westlaw labeled with headnote 12. If you look at the column labeled Headnote(s), you can see which cases (if any) distinguished that point.
Westlaw also uses an orange exclamation point to indicate a case’s risk of being overruled due to its reliance on precedent that has become compromised. The overruling risk indicator is powered by AI, not by lawyer editors, so you will need to carefully make your own assessment of the risk that the point of law you want to cite will be overruled.
For example, Childress v. Heckler, 616 F.Supp. 563 (E.D.La. 1985) has been marked with an orange exclamation point indicating overruling risk.
Westlaw tells you which case indicates that Childress relies on bad precedent: Cadkin v. Loose. If you open Cadkin v. Loose in a new tab and quickly skim, it appears that Cadkin v. Loose overruled Corcoran, a case relied upon by Childress.
Going back to the Childress case, click the small triangle to the right of "Overruling Risk" to open a Document Navigation menu. There, you can click on Overruling Risk to go directly to the portion of Childress that Westlaw identifies as relying on authority that is now bad law. Childress mentions Corcoran (the citation to Corcoran is marked with a red flag because Corcoran has been overruled). However, in reading Childress more carefully, it does not appear that Childress relied on Corcoran. Unlike the plaintiffs in Corcoran and Cadkin v. Loose (which overruled Corcoran), the plaintiff in Childress did not seek a voluntary dismissal. Therefore, as long as your client's situation also does not involve seeking a voluntary dismissal, the overruling risk icon on Childress would not create concern.
Lexis uses a red stop signal to alert you to strong negative history or treatment indicating that the case is no longer good law on at least one point, and a yellow triangle signal to indicate possible negative treatment that is less severe.
For example, the whistleblower decision in Lawson has been assigned a red stop signal because it is no longer valid for at least one point of law.
On the right, under Shepard's®, next to the red stop signal Warning, click Why?
You will see the linked citation to the U.S. Supreme Court case that reversed Lawson.
Click Subsequent appellate history at the right to view the complete history of the Lawson case.
Another way to get there would be to click Shepardize document at the right, then click the History at the top.
Shepard's Appellate History can help you understand the procedural context of the case, chronologically and in terms of which levels of courts have been involved.
United States v. Harrison shows a yellow triangle Shepard's Signal™ because there is possible negative treatment. United States v. Harrison is still good law because it has not been reversed or overruled or superseded by statute. However, before you rely on a yellow-flagged case, you should understand all cases that contributed to its yellow flag and how they could affect the case's precedential value.
To see all the cases that cite Harrison negatively, click Caution under Citing Decisions. (Click the image below to enlarge.)
Because you clicked click Caution under Citing Decisions, a "Caution" filter has been applied, so that only the four decisions that distinguish Harrison are shown. This gives you the opportunity to see whether any of the distinguishing cases are from higher courts in the jurisdiction where you would be arguing. If these cases are not mandatory, then you would not be concerned that any of them would affect the precedential value of Harrison for your purposes.
Once you find a relevant case in Westlaw, you can use the Citing References tab (powered by KeyCite) to find other cases and secondary sources that cite that case.
Click Cases on the left, to see all the cases that cite your case.
You can filter by jurisdiction to look for mandatory case law. The depth of treatment filter for case law represents the extent to which the case that cites your case discusses it (more green bars means more discussion).You can also filter by headnote topic to limit your results to those cases that address a specific legal issue. Select the Apply button to narrow your results.
Click Secondary Sources on the left to see all the secondary sources that cite your case. You can filter by the type of secondary source that cites the case. An ALR annotation can serve as a very helpful case finding tool.
Once you find a relevant case in Lexis, you can use Shepard’s to find other cases and secondary sources that cite that case.
If you do not see Shepard's on the right, click Info to expand the Shepard's panel.
Click Citing Decisions or click Shepardize document. Either option will take you to Citing Decisions by default.
The Citing Decisions are all cases that have cited your case.
The colors on the bar graph show you which courts have analyzed your case from positive or negative perspectives. "Cited by" means that your case was merely cited, without significant analysis. Clicking a vertical bar lets you filter your results to include only cases from one jurisdiction. From there, you can filter to only the positive cases or only the negative cases within that jurisdiction.
To find secondary sources that have cited your case, choose the Other Citing Sources tab at the top.