The law library · United States · District of Nevada
Villanueva v. Las Vegas Metropolitan Police Department: the expert’s ChatGPT history log
Villanueva v. Las Vegas Metropolitan Police Department, Case No. 2:24-cv-00125-ART-DJA · Order on ECF Nos. 70, 71 and 72, Document 112 · District Judge Anne R. Traum · filed 29 September 2026
Order read, nineteen pages; every quotation is from it. Source: the order as filed, from the CourtListener RECAP archive of the court’s docket.
The plaintiff’s expert witness, Tom Melton, used ChatGPT to research and draft his expert report. A magistrate judge had ordered his whole ChatGPT history log produced. On objection, the district judge split it. The case-law summaries ChatGPT produced are “facts or data” the expert considered, and must be disclosed. His questions and prompts, his use of the program to create a deposition outline, and his creation of a draft report stay protected. The objection was granted in part and overruled in part.
Status
- 1 Oct 2025At his deposition, the expert testified that he relied on ChatGPT to assist with researching and drafting his report.
- BelowThe magistrate judge granted the defendant’s motion to compel the expert’s ChatGPT history log in full.
- 29 Sep 2026The district judge granted the plaintiff’s objection in part and overruled it in part.
- The rulesFederal Rule of Civil Procedure 26(a)(2)(B)(ii), on the facts or data an expert considered; Rule 26(b)(4)(B), protecting expert drafts; Rule 26(b)(3)(A), protecting trial preparation material.
What must be disclosed: what the AI produced
“The legal case summaries generated by ChatGPT constitute ‘facts or data’ that Melton considered”
The court gave the reason the other side needs them: “the history log is the only place where Defendant can review alleged ‘hallucinated case citations…quotes…and references to broad legal standards’ that Melton relied upon, or at least considered, to reach his opinion.”
What stays protected: what the expert did with it
The court held it was clearly erroneous or contrary to law to order the entire history produced, because three parts of it are protected:
“Melton’s: 1) questions and prompts to ChatGPT, 2) use of the program to create a deposition outline, and 3) creation of a draft report are all protected from disclosure.”
Prompts are not facts or data, the court reasoned, just as an expert would not consider or rely on their own online research queries, and they reveal the expert’s mental impressions and theory of the case. Drafts are protected “regardless of the form in which the draft is recorded.”
Why it is on this list
The court drew a line through a single AI session: on one side, what the AI produced and the expert considered; on the other, what the expert asked and wrote. Disclosure followed the line.
Where a record keeps those two apart from the start, what the AI produced and what a named person did with it, that line can be drawn without producing everything or nothing.
Sources
- Villanueva v. Las Vegas Metropolitan Police Department, No. 2:24-cv-00125-ART-DJA (D. Nev. Sept. 29, 2026), Order, Dkt. 112, nineteen pages, read for this page
Related
- The law library
- Proposed Federal Rule of Evidence 707, machine-generated evidence
- TRAX International v. United States, AI evaluations in a federal procurement record
Checked against the order. Information, not legal advice.
Information, not legal advice. Every entry is verified against the issuing body’s own document; where a source is reporting rather than the document, we say so.