New Mexico Lawyer Fined $5,000 Over ChatGPT Fabricated Witnesses
New Mexico's Supreme Court fined lawyer Stephen Aarons $5,000 after his ChatGPT brief invented witnesses and testimony in the murder conviction appeal.
Summary
On September 9, 2026, the New Mexico Supreme Court held Stephen Aarons in direct contempt, fined him $5,000 for the State Bar of New Mexico Client Protection Fund, barred him from appearing before it and referred him for disciplinary proceedings that could bring further penalties. Aarons, a criminal defense lawyer for over 40 years, admitted filing an unchecked ChatGPT generated brief in August 2025 for Oscar Renee Sandoval, who received life in prison in February 2025 for killing his partner and children’s mother, Shiereen Al-Jibury. Aarons used a Rev.com trial transcript, the record, issues statement and discovery with ChatGPT powered by OpenAI’s o3 model, released earlier in 2025.
The brief fabricated Officer Michelle Amarillo, Officer Sanchez, Manal Al-Jibury and Teresa Marquez, invented threat testimony involving Danny and Linda Stanton, fabricated shooter descriptions attributed to Mariah Chavez and Marquez, and inaccurately described real precedents. At the August 21 hearing, Aarons claimed he had not known AI could hallucinate and assumed its summary would be reliable, but admitted he neither verified the filing nor told Spanish speaking Sandoval about it, while withholding ChatGPT’s role from Sandoval’s family. The court found a lack of remorse and concern for his client. Justices C. Shannon Bacon, Julie Vargas and Michael Vigil stressed that lawyers remain responsible for accuracy regardless of the tool, with Bacon identifying at least eight or nine potential conduct violations. The court struck all previous briefs, ordered the public defender office to appoint replacement counsel and moved the appeal into its 2026 to 2027 term while Sandoval remains imprisoned.
Positives
- The court struck every previous brief, preventing the fabricated testimony and inaccurate precedent descriptions from remaining in Sandoval’s appeal.
- The public defender office must appoint a new lawyer to prepare a reliable filing for Oscar Renee Sandoval.
- The $5,000 fine is payable to the State Bar of New Mexico Client Protection Fund.
- Justice Michael Vigil confirmed that lawyers may use AI for legal arguments when they independently verify its work.
- Sandoval’s appeal will continue during the New Mexico Supreme Court’s 2026 to 2027 term.
Risks & concerns
- ChatGPT fabricated four witnesses, Officer Michelle Amarillo, Officer Sanchez, Manal Al-Jibury and Teresa Marquez, in a murder appeal.
- The brief invented threat and shooter testimony involving Danny Stanton, Linda Stanton, Mariah Chavez and fabricated witness Teresa Marquez.
- Stephen Aarons filed the August 2025 brief without verifying its factual claims or descriptions of real precedents.
- Aarons did not inform Spanish speaking Oscar Renee Sandoval and withheld ChatGPT’s role from the defendant’s family.
- Sandoval remains imprisoned while replacement counsel restarts briefing in his appeal from a life sentence.
- Aarons faces disciplinary proceedings and possible additional penalties after being barred from the state Supreme Court.
