What does KeyCite actually tell you?
KeyCite is Thomson Reuters' citator for Westlaw. It answers two different questions that students constantly collapse into one. First: what happened to this case procedurally—was it affirmed, reversed, vacated, remanded, or is an appeal pending? That is direct history. Second: what have other courts said about it—have they followed it, distinguished it, criticized it, declined to follow it, or overruled it? That is citing treatment.
KeyCite does not tell you whether the case supports your argument, and it does not tell you whether the specific holding you are quoting survives. A case can carry a red flag because it was reversed on a jurisdictional issue while its substantive analysis of your issue has been cited approvingly a hundred times. The reverse is also true: a case with a clean green-free, flag-free display can contain a footnote that every subsequent court has ignored. The flag is an index, not a conclusion.
What do the KeyCite flags and symbols mean?
Learn the symbols precisely, because on an exam or in a memo you will be asked what they signify, and in practice you will make judgment calls based on them.
- Red flag: the case is no longer good law for at least one point—typically reversed, vacated, or overruled. It does not mean the entire opinion is void.
- Yellow flag: some negative treatment exists but the case has not been reversed or overruled. Common triggers are 'distinguished by,' 'criticized by,' or 'declined to follow by.'
- Blue-striped flag: an appeal is pending, so the decision could change. Flag this in your memo if you are relying on the case.
- Orange warning triangle (KeyCite Overruling Risk): the case itself is intact, but it relies on a point of law from another decision that has since been overruled or invalidated. This is the flag students miss most often.
- Depth-of-treatment bars on citing references: four bars means the citing court examined your case at length; three means discussed; two means cited with brief discussion; one means merely mentioned, usually in a string cite.
- Quotation-mark icon: the citing case directly quotes your case, which is useful when you want language a court has already adopted.
What are the actual steps?
Work through the tabs in order rather than glancing at the flag and moving on.
First, pull up the opinion and read the flag and the 'Most Negative Treatment' line Westlaw displays directly beneath the caption. That line names the single worst thing a court has done to the case. Second, open the Negative Treatment tab. It separates negative direct history (your case was reversed or vacated) from negative citing references (other courts have criticized or refused to follow it). Read the entries, not just the labels. Click into at least the reversing or overruling decision and the two or three most recent negative citing cases.
Third, open the History tab. Westlaw displays direct appellate history, often as a graphical map showing trial court, appellate, and certiorari activity. This is where you confirm which opinion in a chain you should actually be citing. Fourth, open Citing References. This is the largest and most useful tab: it lists every case, brief, secondary source, and administrative decision in Westlaw's database that cites your case.
Fifth, filter. Use the left-hand panel to narrow by jurisdiction (limit to your controlling court), by date (what has happened in the last five years), by treatment (Negative, Distinguished, Declined to Extend), and by depth of treatment (three or four bars only, to skip string cites). Use 'Search within results' with your key terms to find the citing cases that address your issue rather than some unrelated part of the opinion.
How do you check the specific point of law you're relying on?
This is the step that separates competent research from checkbox research. Every Westlaw opinion has numbered headnotes, each tied to a discrete point of law. In Citing References, use the headnote filter to show only the citing cases that discuss the headnote your proposition comes from.
Do it in this order: find the sentence in the opinion you want to cite, scroll up to see which headnote number covers it, then filter citing references to that headnote. If eleven cases have criticized headnote 3 and you are citing headnote 7, your proposition may be fine—but you now know that and can say so. If the negative treatment lands squarely on your headnote, you need a different case.
Also run the Table of Authorities tab, which lists the authorities your case relied on and flags any that have since been undermined. This is how you attack an opponent's lead case: the case itself may be clean, but if it rested on a statute that has been amended or a precedent that has been overruled, its reasoning is vulnerable. That is also the underlying logic of the orange overruling-risk triangle.
How does KeyCite feed your Bluebook citation?
The History tab gives you the raw material for subsequent-history citations under Bluebook Rule 10.7. If a case was affirmed, reversed, or vacated, you generally must append that history, using the italicized explanatory phrases in Table 8—aff'd, rev'd, vacated, rev'd on other grounds, and so on.
Two specifics students get wrong. Denials of certiorari are usually omitted; under Rule 10.7(a)(i) you include cert. denied only when the decision is less than two years old or the denial is particularly relevant. And when a case has been overruled or abrogated, the Bluebook expects you to signal that rather than silently cite it—Table 8 supplies overruled by and abrogated by for that purpose. Check your court's local rules and your professor's instructions, because litigation practice on history parentheticals varies and many courts follow their own citation manual.
Practical framing for a memo: if the case is still good, cite it cleanly. If it has been reversed in part or criticized, cite it with the history and address the treatment in text. Burying negative treatment in a footnote does not satisfy your duty of candor to the tribunal under Model Rule 3.3, and your supervising attorney will find it.
What if you don't have Westlaw?
Citators are proprietary, so the tool depends on your subscription. Lexis uses Shepard's, whose signals map roughly onto KeyCite's: a red stop sign for strong negative treatment, an orange Q for questioned validity, a yellow triangle for possible negative treatment, a green plus for positive treatment, and blue circles indicating that citing references with or without analysis exist. Bloomberg Law uses BCite, which separates 'Case Analysis' (how courts treated the case) from direct history and reports composite positive, distinguished, caution, and negative counts.
The results are not identical. Editors at each service make independent judgment calls about whether a citing case 'criticized' or merely 'distinguished' your authority, and coverage of unpublished and administrative material differs. If your school gives you access to two services and the stakes are high, run both.
Free tools are a supplement, not a substitute. Google Scholar's 'How Cited' shows citing opinions but assigns no negative-treatment signals, so it cannot tell you a case was overruled. Fastcase's Authority Check and similar features detect some negative history algorithmically but are not editorially curated. Do not tell a partner, a judge, or a legal writing professor that you validated a case using Google Scholar alone.
What mistakes should you avoid?
Do not treat a yellow flag as fatal or a missing flag as a clean bill of health. Do not stop at the flag without reading the negative treatment. Do not skip the headnote filter. Do not forget to KeyCite the statutes, regulations, and rules you cite—KeyCite covers those too, and an amended statute quietly wrecks more arguments than an overruled case does.
Timing matters. KeyCite updates continuously, but your research does not. Re-run KeyCite on every authority immediately before you file or submit, and again before oral argument. Note the date you checked. In practice, a case that was good when you drafted and bad when you filed is your problem, not the citator's.