New York / Citation decisions
Deutsche Bank Natl. Trust Co. v LeTennier
App. Div., 3d Dept
2026 NY Slip Op 00040
What happened
In a foreclosure appeal, the defendant’s opening brief cited six cases that did not exist. After the plaintiff flagged the citations and sought sanctions, the defendant’s response and later letters added further fictitious authorities. Defense counsel acknowledged using AI at oral argument while maintaining that the papers had been checked.
The Third Department counted at least 23 fabricated cases across five filings. More than half were submitted after counsel had been put on notice. The court also identified misrepresentations of real decisions and separately found the appeal frivolous. Its sanctions distinguished the AI-related conduct from the pursuit of the appeal itself.
Sanction or disposition
$5,000 on counsel for the GenAI conduct, an additional $2,500 on counsel for the frivolous appeal, and $2,500 on the client for the appeal.
From the opinion
“It is axiomatic that submission of fabricated legal authorities is completely without merit in law and therefore constitutes frivolous conduct”
“the use of GenAI in no way abrogates an attorney’s or litigant’s obligation to fact check and cite check every document filed with a court.”
“Where we are most troubled is that more than half of the fake cases offered by defendant came after he was on notice of such issue”