Citing and Accessing U.S. Law

Fifty years ago, when the nation’s appellate judges and their law clerks researched an issue and cited authority on a point, they worked from and referred to books drawn from a library shelf.  Today, although their many citations employing volume and page numbers evoke that era, judges and those who support them are, nearly always, drawing upon one of two comprehensive digital collections of caselaw, statutes, and commentary, Lexis or Westlaw.  In some jurisdictions subscriptions to both services allow individual judges to choose between them.  That is true of the federal judiciary and many state courts, as well. Some states, however, contract with only one of the competing offerings.  (For background on this point, see How State Courts Contract for Online Legal Information.)

Which of the two digital law libraries, a court or individual judge employs leaves a marker, akin to DNA, in some of the decisions they write. As a consequence, it is possible to investigate these two systems’ respective shares of judicial use.  The telltale trace is left whenever a judge cites a decision that has not yet been (and may never be) compiled into a numbered and paginated volume.  Lexis and Westlaw provide distinctive, proprietary schemes for citing such cases.  The Lexis document identifier includes the term “LEXIS”; Westlaw’s, “WL”.  A search for those unique character strings in a court’s opinions (while still in the form of their initial release and before they have been added to and altered by either commercial system) reveals their authors’ data source.

Such a search is possible on the Courtlistener database maintained by the Free Law Project (www.courtlistener.com).  A Courtllistener search of the 2025 decisions released by the U.S. Supreme Court and Circuit Court of Appeals, as well as those of all state courts of last resort, reveals the following:

• During 2025 the justices of the Supreme Court included numerous “WL” citations in their opinions but not a single “LEXIS” case reference.  Despite their many substantive disagreements, all nine justices appear unanimous in a preference for Westlaw.
• Roughly two thousand 2025 decisions by U.S. Court of Appeals judges cited to Westlaw, fewer than one hundred to Lexis.  (Names can be named.  Judge Frank Easterbrook of the 7^th Circuit appears to be a committed Lexis user.) 
• Among the 2025 decisions rendered by state courts of last resort, “WL” appears in over one thousand, “LEXIS” in fewer than one hundred. The only significant “LEXIS” totals appear in decisions from the supreme courts of Montana and Virginia.

Unfortunately, Courtlistener’s collection of recent U.S. District Court decisions is insufficiently complete for it to be used for a comparable survey.  However, the way Westlaw and Lexis treat judicial citations that employ the other’s proprietary scheme makes it possible to turn their own systems to this purpose. 

Westlaw does not insert parallel LEXIS citations for WL citations when the opinion author has not provided them.  Consequently, a Westlaw search of 2025 U.S. District Court opinions for the term “LEXIS” furnishes a rough measure of Lexis use by district court judges.  Such a search yields a count of 1,438 decisions.  An identical search on the term “WL” retrieves a larger number than Westlaw will total.  

Tellingly, Lexis does add parallel “LEXIS” cites to all those in which a judge has employed a Westlaw “WL” designation.  Consequently, a comparable pair of searches on Lexis produces meaningless results.  However, when a judge’s Westlaw citation includes a star-page pincite, Lexis is unable to provide its equivalent.  A Lexis search designed to retrieve 2025 U.S. District Court opinions containing a WL citation followed by a star-page pincite generates a total of over 90,000.  A comparable search for LEXIS citations with star-page pincites returns fewer than one-sixth that number.

In conclusion, citation analysis using both Westlaw and Lexis reveals that, just as is true with other U.S. courts, when doing caselaw research a large majority of U.S. District Court judges use Westlaw.

The article noted in the preceding post assessed the Supreme Court Reporter’s initiative reducing the lag in attachment of official citations to the Court’s decisions, as of January 2024. The intervening months have seen significant progress. As of August 1, 2024, all the slip opinions of the October 2022 Term and before have been converted to the format in which they will appear in the U.S. Reports, complete with volume and page numbers and editorial revisions. Decisions of the 2023 Term through McIntosh v United States, 601 U.S. 330 (4/17/2024), along with scattered decisions through Garland v. Cargill, 602 U.S. 406 (6/14/2024), have also been moved to U.S. Reports format. No doubt the balance will follow through the summer.

The ritual of citing orders granting certiorari by volume and page number continues to yield citations in the format “See 598 U. S. ––– (2023)”. However, a higher proportion of current citations of opinions from immediately prior terms are now complete. Many citations to earlier decisions of the current term remain in skeletal form (“See, e.g., Fischer v. United States, 603 U. S. –––, ––– (2024) (slip op., at 2) “).

A recent decision of the West Virginia Supreme Court of Appeals quotes a local aphorism that underscores the importance of specificity when citing either to the record or legal authority.  It is to the effect that: “Judges are not like pigs, hunting for truffles buried in briefs.”

Last week the Utah Supreme Court held that the state’s court of appeals had not erred when it refused to consider a laches argument on the ground that it had not been adequately briefed.  Wrote the court:

“We have repeatedly warned that [appellate courts] will not address arguments that are not adequately briefed, and that we are not a depository in which the appealing party may dump the burden of argument and research.” An adequately briefed argument contains “the contentions and reasons of the appellant with respect to the issues presented, including the grounds for reviewing any issue not preserved in the trial court, with citations to the authorities, statutes, and parts of the record relied on.””Mere bald citation to authority, devoid of any analysis, is not adequate. And we may refuse, sua sponte, to consider inadequately briefed issues.”

Johnson v. Johnson, 2014 UT 21, ¶ 20 (citations omitted).