Arajuo v. Wedelstadt
U.S. District Court, Eastern District of Wisconsin · E.D. Wis. · Wisconsin bar guidance
Verified May 14, 2026
- Citation
- Arajuo v. Wedelstadt, No. 23-C-1190, 2025 WL 263529 (E.D. Wis. Jan. 22, 2025) (Griesbach, J.)
- Decided
- January 22, 2025
Summary
Defense counsel Franz J. Maurer filed a brief in support of summary judgment that included citations to nonexistent cases. In his reply brief, counsel admitted using a "new legal research medium" he had not used before, asserting that "[e]ither this medium was corrupt, or the site had been otherwise compromised," and filed an amended brief omitting the fake citations. Judge William C. Griesbach noted that Rule 11(b)(2) requires attorneys to "read, and thereby confirm the existence and validity of, the legal authorities on which they rely," citing Park v. Kim, 91 F.4th 610 (2d Cir. 2024), and stated that to the extent counsel used an AI tool such as ChatGPT that generated fake citations, "this is unacceptable."
- AI tool:
- Unspecified generative AI (court referenced ChatGPT as example)
What sanction did the court impose?
No monetary sanction or formal Rule 11 penalty imposed. The court issued an express warning that "any future filings with citations to nonexistent cases may result in sanctions." The underlying motion for summary judgment was denied on the merits.
Why does Arajuo v. Wedelstadt matter for law firms using AI?
Arajuo is a useful teaching case precisely because nothing was sanctioned. A federal judge caught fabricated citations in a defense brief, accepted counsel’s “the research tool was corrupt” explanation at face value, and let the lawyer off with an on-the-record warning. For a managing partner, the lesson is not that a warning is a soft outcome but that the warning is now a permanent published opinion naming the firm. Future filings by the same attorney, in any court, arrive with this order one search away. Rule 11’s verification duty, as the court reiterated through Park v. Kim, is non-delegable to a vendor or to a tool, regardless of what the marketing copy claims.
Sources
Primary sources
Further reading
Source PDF is a Westlaw printout mirrored from the Damien Charlotin hallucination database. We are working to add the underlying court docket (PACER, CourtListener, or court website) as a second source.