New Mexico court fines lawyer $5,000 for AI-fabricated witnesses in murder appeal

New Mexico’s Supreme Court has fined a lawyer $5,000 and held him in contempt for filing an appeal brief that contained witnesses and testimony invented by artificial intelligence, according to a report from Reuters. The court’s filing, issued Wednesday, found that attorney Stephen Aarons failed to verify the factual claims and legal authority in a brief generated with AI for his client’s murder conviction appeal.

According to the filing, the brief “contained false testimony from wholly fabricated witnesses,” along with false testimony about the clothing and appearance of the shooter in the case. The fabrications were not caught before the brief was submitted to the court.

The case against Aarons came to a head at an August hearing, where he admitted to using ChatGPT, an AI chatbot made by OpenAI, to help prepare the brief. Aarons said he believed the tool would produce what he called a “bulletproof summary” of the trial. Justice C. Shannon Bacon pressed him on how he could have been unaware of the risks of relying on AI-generated legal research. “Counsel, do you watch the news? Do you listen to the radio? Do you read anything about what’s going on in the world?” Bacon said, according to Reuters. “Because the problem with lawyers relying on AI hallucinations is an above-the-fold story every single day.”

A pattern in the courts

Aarons’s case is not the first time a court has caught fabricated AI content in legal filings. As more lawyers turn to AI tools to draft briefs and summaries, courts are increasingly discovering citations, quotations, and even witnesses that the software invented, a phenomenon commonly called hallucination. Last year, a judge criticized two law firms for submitting a brief containing what the judge described as numerous false, inaccurate, and misleading legal citations and quotations. Lawyers representing MyPillow executive Mike Lindell were separately fined after their filing included AI-generated misquotes and fake citations.

In a statement to Reuters, Aarons said he was “remorseful but hopeful that the disciplinary board takes into account it was an honest mistake.” The New Mexico Supreme Court’s filing does not specify further sanctions beyond the $5,000 fine and contempt finding.

What happens next depends on the state’s legal disciplinary board, which Aarons has asked to weigh his case. Reuters’ report does not detail a timeline for that review, nor whether the underlying murder conviction appeal will be affected by the discovery of fabricated material in its brief.