Landberg v. City of New York - attorney sanctioned for AI-generated fabricated citations
A New York court sanctioned an attorney and law firm for submitting a legal brief prepared with generative AI that contained fabricated case citations, fictitious quotations from court decisions, and misrepresentations of case holdings. The court found the AI-generated brief violated professional standards and imposed sanctions on the responsible counsel.
What happened
An attorney and law firm were sanctioned by the Appellate Division, Second Department of New York for submitting a brief prepared with the assistance of generative artificial intelligence containing citations to nonexistent cases and fictitious purported Court of Appeals quotations.
The brief also contained misrepresentations about what certain real cases actually held or decided. The court issued an order to show cause on May 20, 2026, directing the parties to show why sanctions should not be imposed for filing briefs containing fabricated and erroneous legal authority and citations.
Index analysis
The use of generative AI in legal research and brief writing produced unreliable citations that violated professional standards. The fabricated citations and misrepresentations of case law created false legal authority to support arguments in the appeal.
Governance controls
The court imposed sanctions on the attorney and law firm pursuant to 22 NYCRR 130-1.1 for submitting briefs containing fabricated and erroneous legal citations prepared with generative AI assistance.
Classification
Sources and evidence
This record was researched and written by the Index, based on the following original reporting.