New Mexico attorney held in contempt over AI-generated brief

A New Mexico attorney was found in contempt of court after admitting he used ChatGPT to write a legal brief containing fabricated witness testimony. The state Supreme Court removed him from the murder case and ordered him to pay a fine.

Attorney Stephen Aarons told the New Mexico Supreme Court that he “assumed” ChatGPT would generate a “bulletproof summary of proceedings.” “It’s of little comfort to know that my stupidity is what brings us together this afternoon,” Aarons said as he began his arguments.

The appeal concerned a Las Cruces man’s murder case. Aarons acknowledged to justices that he failed to verify the AI-generated text. “I didn’t check the transcript against the summary of proceedings; that’s where my error was,” he said.

Justice David K. Thomson said, “It’s the duty of the lawyer to confirm the facts of the law.”

Justice C. Shannon Bacon pressed Aarons on his awareness of the risks. “Do you watch the news? Do you listen to the radio? Do you read anything about what’s going on in the world? Because the problem with lawyers relying on AI and hallucinations is an above-the-fold story. Every single day,” Bacon said.

The court also criticized Aarons for not telling his client about the mistake and for not answering justices’ questions about how he should be disciplined. “So either you buried your head in the sand, and that’s a choice to do that, an intentional choice to be uninformed, or you took a gamble. And neither of those are consistent with the code of conduct,” Bacon said.

The court found Aarons in contempt, removed him from the case and ordered him to pay a $5,000 fine. Aarons also faces an investigation before the Supreme Court’s Disciplinary Board.

In a statement, Aarons said: “I am cooperating with the disciplinary board and will accept the consequences of my error. In March 2025 I agreed to handle an appeal and used ChatGPT to summarize the trial proceedings. I wrote the brief but the table of contents and the summary contained numerous errors. At the time, I didn’t know that AI could hallucinate facts not only in my brief but also in pleadings submitted by other attorneys in other cases. I support the court’s decision to throw out my defective pleading and appoint another attorney to write a new brief. The most important thing is for my former client to get a fair hearing despite my mistake.”