ChatGPT Put a Fictional Witness in the Appeal

The New Mexico Supreme Court says ChatGPT fabricated police testimony that a lawyer placed in a murder appeal. The generated account attributed statements to an officer who never testified at the defendant’s trial. The court caught the false material and identified it as invented rather than allowing it to stand as an account of the evidence. The ruling is now the corrective record for a filing that should not have reached the judges in that form.

The mechanism is simple. Generated text crossed into a court document without being checked against the trial transcript, admitted exhibits, or docket. This was not merely a citation pointing to a case that did not exist. The software supplied a witness and testimony, counterfeiting the evidentiary layer beneath the legal argument.

ChatGPT cannot inspect the official record unless someone provides it, and even then its summary remains a claim to verify. The human duties do not move. Counsel must know what the transcript says, distinguish quotation from paraphrase, preserve relevant source material, and correct the filing when a statement cannot be authenticated. A fluent paragraph is not a record check.

The court system also needs enough information to reconstruct the failure. That includes the prompts and responses used to prepare the appeal, the model version, any sources displayed by the service, the filing’s revision history, and the transcript pages counsel believed supported the disputed passage. Without those materials, judicial review can identify the fabrication but not determine how it survived drafting and submission.

Sanctions are only one part of the remedy. The defendant should receive direct notice of every unsupported claim, and the public docket should preserve both the defective version and a clearly labeled correction. Quiet replacement would make the archive cleaner by making the mistake harder to study. Courts need the opposite: a durable account of what entered the file, who discovered it, and what changed.

The authentication rule should be blunt. No AI-assisted factual assertion about testimony or evidence enters a permanent legal filing unless counsel can attach it to a specific transcript page, exhibit, or docket item and certifies that a person checked the match. If that link does not exist, neither does the witness.