US lawyer sanctioned for filing appeal brief with ChatGPT-fabricated witness testimony
New Mexico's Supreme Court held defense attorney Stephen Aarons in contempt after he submitted an appeal brief containing fake testimony generated by ChatGPT. The case will now proceed with a new lawyer.
The New Mexico Supreme Court has held longtime criminal defense attorney Stephen Aarons in direct contempt of court after he filed an appeal brief containing entirely fabricated witness testimony, including invented statements attributed to police officers. The court referred him to a disciplinary board, finding he showed a lack of remorse and insufficient concern for his client.
Aarons, who has practiced criminal defense in New Mexico for more than 40 years, was hired by family members of a man convicted of murder to handle his appeal. The client had been sentenced to life in prison in February 2025 for killing his partner. In August 2025, Aarons filed a brief containing false testimony from several nonexistent witnesses and inaccurate descriptions of prior case law.
Trial transcript fed into ChatGPT
At an August hearing, Aarons admitted he had entered case documents, including a computer-generated trial transcript, into ChatGPT using a version powered by OpenAI's o3 model, and assumed the resulting summary was accurate without verifying it. He said he had not been aware that AI tools could hallucinate facts.
Justice C. Shannon Bacon strongly criticized Aarons, stating he had violated at least eight or nine provisions of the code of professional conduct. She expressed skepticism about his claimed ignorance, noting the issue of lawyers relying on AI-generated falsehoods has been widely reported for years.
Aarons did not tell his client or the client's family that ChatGPT had been used, only informing them that an issue had arisen with the filed brief. The court said the client deserved to know the full extent of the problem in order to decide whether Aarons should continue representing him.
Aarons has been barred from appearing before the state Supreme Court pending the disciplinary board's investigation and was fined $5,000, payable to the State Bar of New Mexico's Client Protection Fund. The court ordered a public defender to be appointed for the client, struck all prior briefs from the record, and said the case will proceed in its next term.
