New Mexico Court Sanctions Attorney for Submitting AI-Generated False Testimony in Murder Appeal

The New Mexico Supreme Court found attorney Stephen Aarons guilty of direct contempt for filing a brief containing "false testimony from wholly fabricated witnesses," including invented police officers and other inaccurate material. The court determined that Aarons "demonstrated a lack of remorse and a lack of concern for his client" and has referred him to a disciplinary board for additional proceedings.

Aarons, a criminal defense attorney with more than four decades of experience in New Mexico, was retained by family members of Oscar Renee Sandoval to challenge a murder conviction. Sandoval received a life sentence in February 2025 following his conviction in the death of Shiereen Al-Jibury, his partner and the mother of his children. In August 2025, Aarons submitted the problematic brief, which the state subsequently moved to strike in part.

According to the court's ruling, Aarons "admitted to the Court that he did not verify the factual claims and legal authority in his AI-generated brief before signing it and filing it with the Court, and that he did not inform his client of this failure or that the brief in chief contained multiple factual and legal misrepresentations."

Fabricated Witnesses and Inaccurate Case Citations

The court order identified multiple fabricated witnesses cited in Aarons' brief: Officer Michelle Amarillo, Officer Sanchez, Manal Al-Jibury, and Teresa Marquez. The brief also contained false statements attributed to Danny Stanton regarding threats he allegedly received, false testimony from Linda Stanton about threats her husband faced, and inaccurate descriptions of witness accounts from Mariah Chavez and Teresa Marquez regarding the shooter's appearance and clothing.

While Aarons did not cite entirely fabricated cases, he misrepresented real precedents in his citations. The distinction between citing nonexistent cases and inaccurately describing actual ones proved immaterial to the court's analysis.

Aarons explained that he had fed a computer-generated transcript of the murder trial and related case documents into ChatGPT, which then generated the false quotations. At an August 21 hearing before the state Supreme Court, he stated, "It's of little comfort to know that my stupidity is what brings us together this afternoon." He acknowledged that his brief included quotations from witnesses never called at trial, a witness whose name was incorrectly stated, and inaccurate summaries of legal precedent.

Aarons indicated he had employed ChatGPT using the OpenAI o3 model, released earlier in 2025. He expressed his assumption that the tool would generate reliable output, noting that "I assumed that it generated a bulletproof summary of proceedings." He justified this reliance by pointing to widespread AI adoption in legal and medical professions.

Court Sanctions and Disciplinary Action

The New Mexico Supreme Court barred Aarons from appearing before it pending the outcome of disciplinary proceedings and imposed a $5,000 fine payable to the State Bar of New Mexico Client Protection Fund. Additional penalties may result from the disciplinary board investigation. The court ordered the public defender office to appoint new counsel for Sandoval, removed all previous briefs from the record, and scheduled the case to proceed during the 2026-27 term.

Justices Question Aarons' Awareness of AI Limitations

During the hearing, justices expressed skepticism about Aarons' claim that he was unaware AI systems could generate false information. They emphasized that attorneys bear ultimate responsibility for verifying accuracy regardless of the source—whether assistance comes from AI, law students, or colleagues. Any lawyer who signs a brief must vouch for its correctness.

Justice C. Shannon Bacon delivered particularly sharp criticism, informing Aarons that he had violated "at least eight or nine provisions in the code of conduct." She expressed difficulty accepting his claim of ignorance about AI hallucinations, noting that her 13-year-old nephew and 75-year-old stepmother both understand the problem.

Bacon stated: "So counsel, 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 hallucinations is an above-the-fold story every single day. 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."

Aarons responded that he had submitted the brief a year prior and that much information about AI risks had emerged since then. However, reports of lawyers citing fabricated cases through AI assistance have circulated in legal media for more than three years. When Aarons noted that the cases he cited were real, though misdescribed, Bacon countered that no meaningful distinction exists between citing a nonexistent case and inaccurately describing an actual one, as professional conduct rules apply equally in both scenarios.

Aarons' Statement and Process

In a statement to the press, Aarons said: "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 in pleadings submitted by other attorneys. I am glad the court threw out my defective pleading and ordered the public defender to write a new brief on behalf of my former client. As for myself, I am remorseful but hopeful that the disciplinary board takes into account it was an honest mistake. It is a lesson learned for all professionals who rely upon this powerful but sometimes unstable technology."

Aarons described his workflow: he used Rev.com, a service providing AI-generated transcripts of audio recordings, to obtain a trial transcript, then input that transcript along with other materials into ChatGPT. When asked whether he had verified the transcript's accuracy before feeding it into ChatGPT, he responded, "I believe I did confirm" its accuracy, but added that "The problem wasn't in the transcript. It was when I loaded it and all the other information" into ChatGPT. Beyond the transcript, he loaded "the record proper, the statement of issues, and some of the discovery" into the system.

Aarons suggested the court consider issuing a standing order requiring briefs to include a certificate of compliance documenting AI use. Justices dismissed this proposal as a distraction from the core issue: Aarons' failure to verify the brief's accuracy. Justice Bacon responded: "Assume with me that you had relied on the work of a first-year lawyer that was working for you and that they had just made stuff up… and you signed it. You'd be in the same exact soup you are right now. So the idea that, the suggestion in your briefing that because the court didn't tell you at the time that you did this, 'be careful,' it somehow relieves you of obligation, falls on absolute deaf ears because the rules of professional conduct already tell you what your obligation is."

Impact on the Defendant

Bacon also criticized Aarons for failing to address the harm to his client. She stated: "The other thing that's completely missing from your response is anything about what this has done to your client. That's who I'm worried about. You have presented briefing to the court that we cannot rely on, and your client is the one suffering because of this far more than you will ever suffer."

Chief Justice Julie Vargas expressed frustration with Aarons' focus on broader policy questions rather than addressing the immediate situation. She told him: "I'm really interested with the approach you're taking in this hearing. You seem to be telling us all the policy that we've been thinking about for years about what to do with AI, but you're not talking about how to address the situation that's in front of us, which has significant impacts on a criminal defendant who is in custody, who's going to stay in custody until we resolve this matter. And I really don't care about the policy concerns right now. I care about what we're going to do with your client and what we should do in this circumstance based on the behavior that you showed us."

Justice Michael Vigil stated that using AI to assist with legal writing is permissible provided the attorney verifies accuracy. He said: "It doesn't matter what the tool is. It doesn't matter how advanced the AI-generated program is or what improvements they make, whatever. It doesn't matter whether you use a C-student lawyer or a A-student lawyer [if] you didn't check their work before you filed the brief. That's the issue. And I wish, or I'm hoping you would focus on that, take responsibility for it."

Aarons replied: "I hope I don't present myself as not accepting responsibility. I mean, my only hope is that the mistakes that I made that somehow can prevent someone else down the line from repeating my mistake because the AI capacity is amazing."

Failure to Disclose to Client and Family

Bacon also criticized Aarons for not disclosing the problem to Sandoval. When asked if he had informed his client, Aarons responded, "I have not. He's a Spanish speaker and I wanted to see what happened today." Aarons stated he had been hired by Sandoval's brother and cousin and had told them only that there was a problem with the brief. "They're aware that there was a problem with the first brief that I filed and that the court's looking at that. That's pretty much it," he said.

Bacon pressed the point: "You didn't say, 'I relied on ChatGPT and it submitted lies to the court and the court is mad at me and now there's a hearing.' I'm guessing you didn't tell your client's family members that." Aarons acknowledged, "I didn't talk about ChatGPT. I just said there was a problem with the brief that I filed." Bacon told Aarons that his client needed full disclosure to make an informed decision about whether Aarons remained the appropriate representative.

When asked whether he was working under a public defender contract or as private counsel, Aarons indicated he had been hired as private counsel but had not yet received payment. Bacon replied, "I'm not sure that's going to happen."