New Mexico Supreme Court fines lawyer $5,000 over ChatGPT-fabricated witnesses

September 12, 2026 at 01:42 AM2 min

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The New Mexico Supreme Court fined attorney Stephen Aarons $5,000 and held him in contempt for filing an appeal brief containing fabricated witness testimony generated by ChatGPT. The court said the brief included false testimony from wholly fabricated witnesses and fictional statements about the shooter's clothing. Aarons said he used ChatGPT to summarize trial proceedings and did not understand the degree to which AI could hallucinate facts.

Key Facts

The New Mexico Supreme Court fined attorney Stephen Aarons $5,000 and held him in contempt on Wednesday.
Aarons' appeal brief for murder convict Oscar Renee Sandoval contained false testimony from wholly fabricated witnesses.
Justice C. Shannon Bacon asked Aarons, 'Counsel, do you watch the news?' during an August hearing where he admitted using ChatGPT.
The court will refer Aarons to an attorney disciplinary board for investigation.
The appeal was assigned on September 2 to Kim Chavez Cook, a New Mexico public defender.

Court Sanction

The New Mexico Supreme Court fined attorney Stephen Aarons $5,000 and held him in contempt for failing to verify the accuracy of his court filing. The filing contained false testimony from wholly fabricated witnesses and fictional statements that the shooter was wearing dark pants and a white shirt. The court said Aarons demonstrated a lack of remorse and a lack of concern for his client. The justices will refer Aarons to an attorney disciplinary board for investigation.

AI Hallucination Admission

Aarons said he used ChatGPT to summarize trial proceedings when he agreed to take up the defendant's appeal last year. He stated he did not understand the degree to which AI could hallucinate facts. During an August hearing, Justice C. Shannon Bacon asked Aarons, 'Counsel, do you watch the news? Do you listen to the radio? Do you read anything about what's going on in the world?' Aarons said he is remorseful but hopeful the disciplinary board takes into account it was an honest mistake.

Case Background

Aarons, a private attorney based in Santa Fe, was handling the appeal of Oscar Renee Sandoval. Sandoval pleaded not guilty to the murder of the mother of his children before he was convicted and sentenced last year to life in prison. The appeal is still pending and was assigned on September 2 to Kim Chavez Cook, a New Mexico public defender. The state supreme court last month ordered Aarons to explain how the fabricated material was included in his primary brief.