Seventh Circuit Sets Rules for Lawyers on AI Hallucinated Citations
Seventh Circuit rules lawyers must verify AI-generated citations in legal briefs.
Why it matters: With AI tools increasingly used in legal drafting, this ruling clarifies ethical and litigation risks attorneys face. It underscores the necessity of verifying all citations despite AI assistance to maintain court integrity and comply with professional standards.
- June 2, 2026, ruling by Seventh Circuit in Dec v. Mullin case.
- Court fined primary attorney $5,000 and revoked admission for copying unverified AI hallucinated citations.
- Attorneys must personally read and confirm accuracy of all citations, whether AI-generated or not.
- Opposing counsel also has a duty to check citations to preserve legal document integrity.
On June 2, 2026, the Seventh Circuit Court of Appeals issued a pivotal ruling in Dec v. Mullin that addresses the responsibilities of attorneys when using AI-generated content in legal briefs.
The court sharply criticized counsel for copying citations from an earlier brief without verifying them, resulting in references to fabricated cases and false quotations. This hallucinated content, produced by AI tools mistakenly as factual information, led to sanctions including a $5,000 fine and revocation of court admission for the primary attorney involved.
The ruling clarified that "no brief, pleading, motion, or any other paper filed in any court should contain any citations—whether provided by generative AI or any other source—that the attorney responsible for submitting the pleading has not personally read and verified." This explicit instruction makes clear that attorneys cannot rely blindly on AI outputs.
Moreover, the court recognized the growing prevalence of AI in legal practice and cautioned that such tools “can produce output that is fictional, inaccurate or nonsensical.” Aligning with this, it noted the shared duty of opposing counsel to check citations and report errors, as they too failed to flag the hallucinated references in this matter.
The court's decision underlines ethical obligations and litigation risk management as AI use becomes more common and sophisticated in legal drafting. It is a call for lawyers to exercise due diligence and confirms the courts’ intolerance for hallucinated legal content that jeopardizes the integrity of court filings.
By the numbers:
- June 2, 2026 — date of the Seventh Circuit ruling
- $5,000 — fine imposed on primary attorney for unverified AI hallucinated citations
- 17% to 33% — estimated hallucination rates in AI legal research tools
Yes, but: The ruling does not provide specific enforcement mechanisms or detailed guidance on best practices for verifying AI-generated content, leaving some uncertainty about compliance methods.
What's next: As AI tools evolve, courts and bar associations may issue further guidance or rules on managing AI-generated content in legal pleadings.