How can I tell if a court case exists?
<p>As someone without access to pricy legal search engines, how can I tell if a given case exists?</p>
<p>For context, a lawyer was recently found to have cited a number of cases hallucinated by ChatGPT.  The <a href="https://storage.courtlistener.com/recap/gov.uscourts.nysd.575368/gov.uscourts.nysd.575368.46.1.pdf" rel="nofollow noreferrer">transcript of his ChatGPT session</a> is now online.  ChatGPT cited 39 cases in response to queries by the lawyer; I'd like to see how many of them are real.  Some, such as <em>Bell Atlantic v. Twombly</em> are easy &quot;yes&quot;s: they've got Wikipedia articles.  Six of them, such as <em>Varghese v. China Southern Airlines</em>, are easy &quot;no&quot;s: they were called out as fake in the court filings.</p>
<p>But what about the remaining cases?</p>

<p>A properly cited case will include a reference to <a href="https://law.stackexchange.com/questions/89453/how-to-decode-a-citation-to-a-case-reporter">a case reporter, online database, or neutral citation</a>. To confirm that the case exists, you would have to track down the purported reporter/journal/database and query whether the case exists at that location.</p>
<p>There is <a href="https://law.meta.stackexchange.com/questions/261/online-legal-references">a meta post</a> that presents online legal research tools. Many universities and courts have <a href="https://en.wikipedia.org/wiki/Public_Law_Libraries_(U.S.)" rel="nofollow noreferrer">public law libraries</a> that have access to printed reporters and/or online databases.</p>

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<p>For absolute certainty, you could do what the court in the linked Chat-GPT case did: contact the clerk of the court that issued the alleged opinion and ask if that opinion really exists.</p>
<p>In the case of cases reported in the various leading case reporters, however, free Google searchable services will generally have full text copies that can be found online. These resources have close to 99% of published appellate court opinions that are reported in recognized case reporters in the U.S. Secondary materials are often hard to get online for free, but primary legal authorities are usually easy to find.</p>
<p>Westlaw, Lexis, and some specialized subject matter services like tax publishers, often also have unpublished or unreported decisions that would not be revealed by such a search. But, while the vast majority of cases decided are unpublished, the vast majority of cases cited in legal briefs are published decisions that are reported in recognized case reporters. And, in some courts, citations to unpublished opinions, must be accompanied by the full text of those decisions or are entirely forbidden.</p>
<p>So, you could restrict inquiries to court clerks to cases whose existence is not verified from free sources on the Internet.</p>

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