On September 9, 2025, the Superior Court of California, County of Alameda issued a significant order in the matter of Ariel and Maridol Mendones v. Cushman & Wakefield, Inc., et al. (Case No. 23CV028772).
The Court imposed a terminating sanction—the dismissal of the case with prejudice—after finding that the plaintiffs had submitted falsified evidence generated with artificial intelligence.
The plaintiffs had filed a motion for summary judgment, a procedure allowing judgment without trial when no genuine dispute of material fact exists. To support their motion, they submitted multiple videos, photographs, and messaging screenshots presented as witness testimony or admissions.
Upon review, the Court determined that several of these exhibits were deepfakes or otherwise altered using generative AI, including:
The purpose of these submissions was clear: to create an artificial body of evidence that would support summary judgment in the plaintiffs’ favor.
The Court relied on California Code of Civil Procedure § 128.7, which requires parties to certify that their submissions have evidentiary support and are not presented for improper purposes.
The Court also recalled provisions of the California Penal Code on perjury (§ 118) and forgery (§ 470). However, it declined to refer the matter to the District Attorney, finding that criminal referral would be disproportionate and not directly remedial in the civil proceeding.
The judge concluded that plaintiffs had violated § 128.7(b) by presenting fabricated evidence. Lesser sanctions such as monetary penalties or evidentiary exclusions were deemed insufficient.
Accordingly, the Court imposed the most severe remedy:
The Court emphasized that the use of deepfakes fundamentally undermines the integrity of judicial proceedings and warrants a strong deterrent message: zero tolerance for AI-generated falsifications presented as evidence.
This decision goes beyond earlier sanctions imposed for fictitious case citations generated by AI (Mata v. Avianca, Inc., U.S. v. Hayes). It addresses for the first time in a civil trial context the deliberate use of deepfake evidence.
The ruling highlights the urgent need for litigants and counsel worldwide to ensure the authenticity of digital evidence before submitting it in court, and illustrates how courts may respond with drastic measures when the trust placed in the judicial process is deliberately breached.
Full text of the decision (PDF)
