EDNY sanctions counsel $1,000 for AI-assisted nonexistent case citations in Ramirez v. Humala

On 13 May 2025 United States District Judge Rachel P. Kovner of the Eastern District of New York sanctioned attorney Lina Stillman and her firm Stillman Legal, P.C. $1,000 jointly for citing nonexistent authority in a filing in Ramirez v. Humala, No. 24-CV-242 (RPK) (JAM).

The order opens with the concrete filing error. On 21 April 2025 defendant Carlos Humala moved for a pre-motion conference ahead of an anticipated motion to dismiss. Plaintiff Abigail Ramirez’s response letter, filed the same day and signed by Stillman, cited eight cases. The Court could not locate four: London v. Polish Slavic Fed. Credit Union, No. 19-CV-6645, 2020 WL 1275619 (E.D.N.Y. Mar. 17, 2020); Rosario v. 2022 E. Tremont Hous. Dev. Fund Corp., No. 21-CV-9010, 2023 WL 1993700 (S.D.N.Y. Feb. 14, 2023); Paniagua v. El Gallo No. 3 Corp., No. 22-CV-7073, 2024 WL 1046856 (S.D.N.Y. Mar. 11, 2024); and Luna v. Gon Way Constr., Inc., No. 20-CV-893, 2022 WL 826856 (S.D.N.Y. Mar. 18, 2022). The Court ordered Stillman to provide copies or show cause why she should not be sanctioned under Federal Rule of Civil Procedure 11(b) and the Court’s inherent power.

The affidavits that followed are the detail usually flattened into “AI hallucinated cases.” Paralegal Abigail Ruiz stated she had assisted with legal research for the reply and generated the citations “using secondary tools, including public search resources and AI-based research assistants,” without checking that the citations corresponded to real cases before passing them to Stillman. Stillman attested that she relied on Ruiz as “a diligent and trusted member” of the team and “did not independently verify each citation prior to filing.” Stillman conceded the cases do not exist.

Judge Kovner held that Rule 11(b)(2) requires an inquiry reasonable under the circumstances that contentions are warranted by existing law; citing Mata v. Avianca, Inc., she noted a fake opinion is not existing law. She found Stillman violated Rule 11 by failing the minimal duty to read and confirm the authorities relied on, and — for sua sponte sanctions — that subjective bad faith could be inferred from a failure to make any inquiry into the citations’ veracity. Comparable AI-citation sanctions cited in the order have ranged from $1,000 to $5,000, sometimes with nonmonetary measures. Here the Court imposed a sanction at the low end because of Stillman’s prompt admission, the apologies from Stillman and Ruiz, and Stillman’s averment that the firm was reviewing citation practices so future research-based citations would be pulled from Westlaw or PACER and verified by a supervising attorney. Stillman Legal, P.C. is jointly responsible under Rule 11(c)(1). The $1,000 is to be paid into the court registry within fourteen days; Stillman must also serve a copy of the order on her client and file proof of service within fourteen days.

The pattern is invented-source: secondary and AI research tools produced case-shaped strings that looked citable. The court treated the filing system as still requiring a human to confirm that each authority exists before the signature goes on the paper.