Immigration attorney hit with sanctions for using Claude to generate fake case citations

A federal court imposed sanctions on a petitioner’s attorney for submitting fabricated legal quotations generated by the AI tool Claude Sonnet 4 in an emergency habeas case seeking to halt a client’s deportation. Facing an expedited timeline and suffering from a respiratory infection, the attorney admitted he used AI to draft a supplemental brief and failed to verify the quotations, despite knowing AI tools are prone to hallucinations.

The court found this conduct violated Rule 11 and constituted subjective bad faith, noting that the attorney either consciously avoided checking his sources or deliberately ignored the opposing party’s warning about the fake quotes.

While courts have typically imposed monetary sanctions ranging from $1,500 to $15,000 in similar cases, the court here imposed a reduced $1,000 fine in light of mitigating factors, including the attorney’s prompt admission, withdrawal of the filing, and enrollment in a continuing legal education (CLE) course on ethical AI use. He was also ordered to file proof of CLE completion.

The decision underscores that AI use in legal practice does not excuse attorneys from their duty to confirm the accuracy of filings and that even in emergency settings, courts will hold lawyers accountable for unverified, fictitious legal content.

Kaur v. Desso, 2025 WL 1895859 (N.D.N.Y. July 9, 2025)