New Mexico Court Fines Lawyer $5,000 Over AI-Fabricated Witnesses

Generative AI is increasingly used to review records and draft legal filings, but large language models can produce plausible falsehoods unless their output is checked. The case involving New Mexico defense lawyer Stephen Aarons is significant because the errors went beyond invented citations: a murder-appeal brief included nonexistent witnesses and fabricated testimony. It underscores that lawyers remain accountable for the factual record and legal authorities they submit, regardless of whether OpenAI’s ChatGPT helped prepare the document.

The New Mexico Supreme Court on Sept. 9, 2026, held Aarons in direct contempt and fined him $5,000, payable to the State Bar of New Mexico Client Protection Fund. At an Aug. 21 hearing, he admitted he had not verified the AI-generated factual claims or legal authorities. The court struck the prior briefs, ordered the public defender’s office to appoint replacement counsel, barred Aarons from appearing before it pending disciplinary proceedings and said the appeal would proceed in its 2026-27 term.