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Key Takeaways

• A New Mexico defense attorney was held in direct contempt after filing a murder appeal brief containing fabricated witnesses and false testimony generated with ChatGPT.
• The state Supreme Court fined attorney Stephen D. Aarons $5,000, struck the appellate briefs and referred him to the attorney disciplinary board.
• The case goes beyond the now-familiar problem of AI inventing legal citations because the filing inserted testimony from people who never testified—and, in several instances, apparently never existed.

By Samuel López | USA Herald

A New Mexico attorney who turned to ChatGPT for help preparing a murder appeal is now facing professional discipline after the state's highest court concluded that his filing contained invented witnesses, fabricated testimony and misrepresentations of legal authority.

The New Mexico Supreme Court on September 9 held attorney Stephen D. Aarons in direct contempt of court and ordered him to pay $5,000 to the State Bar of New Mexico Client Protection Fund within 30 days. The court also barred Aarons from appearing before it while disciplinary proceedings are pending.

The consequences did not stop with the fine.

The justices referred Aarons to the Disciplinary Board, removed his briefing from the appeal and directed the Law Office of the Public Defender to take over representation of his former client, Oscar Renee Sandoval.

Sandoval was convicted of murdering Shiereen Al-Jibury, his partner and the mother of his children, and was sentenced to life in prison in February 2025. His appeal remains pending.

AI Did More Than Invent Case Citations

What makes this case particularly striking is the nature of the hallucinations.

Courts across the country have already sanctioned attorneys after generative AI produced nonexistent cases or inaccurate descriptions of real decisions. Here, however, the errors reached directly into the purported evidentiary record of a murder prosecution.

According to the Supreme Court's order, Aarons admitted that his brief contained “false testimony from wholly fabricated witnesses.”

The court specifically identified Officer Michelle Amarillo, Officer Sanchez, Manal Al-Jibury and Teresa Marquez as fabricated witnesses. The filing also attributed false testimony to actual witnesses Danny Stanton, Linda Stanton and Mariah Chavez, including statements concerning alleged threats and the shooter's appearance.

The brief additionally misrepresented legal authority from two New Mexico Supreme Court cases.

That distinction matters. An invented legal citation can mislead a judge about the law. Fabricated testimony can distort what supposedly happened at trial—an especially serious problem when a defendant is serving a life sentence.

Lawyer Says He Expected a ‘Bulletproof Summary’

At an August 21 hearing, Aarons told the justices that he had supplied ChatGPT with a computer-generated transcript and other case materials because he believed the system would generate what he described as a “bulletproof summary.”

Aarons later told Reuters that he did not appreciate the extent to which generative AI could hallucinate information and characterized what happened as an honest mistake.

The Supreme Court was considerably less forgiving.

Its written order states that Aarons admitted he did not verify the factual claims or legal authorities generated through AI before signing and filing the brief. He also admitted that he had not informed Sandoval about those failures or the misrepresentations contained in the filing.

The court ultimately concluded that Aarons had demonstrated “a lack of remorse and a lack of concern for his client.”

Justice C. Shannon Bacon was equally pointed during the hearing, questioning how an experienced attorney could remain unaware of the highly publicized risk of AI hallucinations. Bacon described lawyers relying on AI hallucinations as an issue appearing in the news “every single day.”

The Lawyer Still Owns the Filing

The decision underscores a principle that is becoming increasingly difficult for the legal profession to ignore.

Artificial intelligence may assist with research, transcription, summarization and drafting, but it does not assume an attorney's professional obligations.

The lawyer whose name appears on the filing remains responsible for verifying the facts, checking the authorities and ensuring that representations made to a court are supported by the record.

The Supreme Court struck all briefing previously filed in Sandoval's appeal and ordered that new briefing begin under newly appointed counsel. The court said it intends for the appeal to be heard during its 2026–2027 term.

The disciplinary process could determine whether Aarons faces additional professional consequences.

Read the New Mexico Supreme Court's September 9 order in State v. Sandoval

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