New Mexico Court Fines Lawyer Over ChatGPT-Fabricated Testimony in Murder Appeal

Aarons had agreed last year to take up the appeal of a client's murder conviction, he said in a statement to Reuters. He said he used ChatGPT to summarize the trial proceedings and did not understand the degree to which the AI could "hallucinate" facts. "I am remorseful but hopeful that the disciplinary board takes into account it was an honest mistake," Aarons said.

The filing appears to have gone further than earlier AI-related legal errors. Dozens of lawyers have been sanctioned for submitting briefs in which AI invented case citations or misquoted the law. Aarons's filing contained fabricated witness testimony in a criminal appeal, Reuters reported.

At an August 21 hearing, Aarons told the court that he had fed a computer-generated transcript and other case materials to ChatGPT. He said he presumed the program would generate "a bulletproof summary," according to the report.

The justices were incredulous that Aarons was not fully aware of how AI can make mistakes. "Counsel, do you watch the news? Do you listen to the radio? Do you read anything about what's going on in the world?" Justice C. Shannon Bacon said at the hearing. "Because the problem with lawyers relying on AI hallucinations is an above-the-fold story every single day."

OpenAI did not immediately respond to a request for comment, Reuters reported. The New Mexico Supreme Court's order adds to sanctions against lawyers who rely on generative AI without checking its output, though the Aarons case drew particular attention because the AI-generated material included witness testimony in a criminal appeal.