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A Missouri appellate court has ordered an attorney to pay $1,750 of the opposing parties' attorney's fees for filing pleadings that cited cases which do not exist, while stating on the face of the opinion that it is not sanctioning her for using generative AI
The sanction is not the story. This one is worth reading for a single paragraph, in which the court takes the tool out of the holding and leaves only the unverified filing.
Bottom line: Binding on the parties and on relator's counsel. Filed 8 September 2026. The writ petition is denied and counsel is ordered to pay $1,750 to the petitioners in the underlying action for the attorney's fees they incurred answering the petition.
Who this affects: Missouri litigators and appellate practitioners, law firm risk and ethics counsel writing AI verification policies against a state rule and not Rule 11, and self-represented parties filing in the Missouri appellate courts.
Issue date: Filed 8 September 2026. No deadline runs from the opinion; the fee award is stated as a total amount payable, without a payment date on the face of the opinion.
What changed: A state appellate court put on the record that the sanction does not attach to the use of generative AI. It attaches to filing pleadings citing cases that do not exist, which the court equates to signing your name to someone else's unverified work.
Analysis: The reasoning runs through Rule 55.03's objective standard. Because fabrication by generative models is treated as well documented, the court reaches the conclusion that failing to verify is objectively unreasonable, and says that ground alone supports the sanction.
Primary sources: Opinion in State of Missouri ex rel. Schnell v. Richardson, No. ED114731
- Instrument (EN)
- Opinion denying an original writ of mandamus and imposing a monetary sanction under Rule 55.03
- Authority
- Missouri Court of Appeals, Eastern District, Writ Division Four. Torbitzky P.J., with Page J. and Wright J. concurring
- Jurisdiction
- United States, Missouri state appellate
- Status
- Filed and decided. Writ denied, sanction imposed
- Bindingness
- Binding on the parties. The court expressly makes no decision on whether any rule of professional conduct was violated
- Issue date / next deadline
- Filed 8 September 2026. No deadline is set in the opinion
- Number
- ED114731
- Legal basis
- Missouri Supreme Court Rule 55.03(b) and 55.03(c)
- Primary source
- https://www.damiencharlotin.com/documents/3051/State_of_Missouri_v._Richardson_USA_8_September_2026.pdf
The sentence that separates the tool from the wrong
Counsel told the court, in response to a show cause order, that she had used generative artificial intelligence to research legal authorities and had not verified the citations before filing.
The opinion then goes further, and the paragraph in which it does so is short enough to quote whole. "To be clear, this Court is not sanctioning Conley because she used generative AI. The use of AI is only incidental to the sanction. There is nothing inherently problematic from a briefing perspective with the use of generative AI. Rather, the sanction is appropriate because Conley filed pleadings in this Court that cited cases that do not exist for unsupportable propositions."
The court then supplies the analogy it wants read alongside that: "In this respect, it is no different than if Conley signed her name to work prepared by someone else without verifying the accuracy of claims therein." That is a deliberate relocation of the wrong. The conduct being punished is the signature on unverified work, and the identity of whatever produced the work drops out.
Why the objective standard does the heavy lifting
Rule 55.03(b) provides that by presenting a claim or argument in a filing, an attorney certifies that, after an inquiry reasonable under the circumstances, the legal contentions are warranted by existing law or by a nonfrivolous argument to extend, modify or reverse it. The opinion quotes State ex rel. Accurate Const. Co. v. Quillen for the proposition that the rule "imposes an objective standard of conduct", with the emphasis in the original.
The court finds two violations. The first is almost definitional: for a claim to be warranted by existing law, the law supporting it has to exist, and by counsel's own admission these cases did not. The second is the prefiling inquiry, and that is where the AI reasoning sits.
The chain is explicit. "At this point in time, generative AI's tendency to fabricate caselaw and citations is well documented." From that premise the court reaches its conclusion: "Given the well-known tendency of generative AI models to make fabrications, it is objectively unreasonable for any attorney or self-represented party to fail to verify AI's accuracy. For this reason alone, sanctions are appropriate."
Note the reach of that formulation. It is written for any attorney or self-represented party, not for this one, and the court does not simply assert the premise, it grounds it in published authority: Kruse v. Karlen, Mata v. Avianca, State v. Coleman on fabricated transcript quotations, and a 2026 Journal of the Missouri Bar article. A footnote records the scholarly argument that confabulation is a more accurate term than hallucination, citing a Suffolk Law research paper.
The professional conduct map, and the decision the court refused to make
Having disposed of the sanction, the opinion walks through the Missouri Rules of Professional Conduct that careless AI use can implicate: Rule 4-1.1 on competence, whose comments require maintaining knowledge of "the benefits and risks associated with relevant technology"; Rule 4-3.1 on a basis in law and fact; Rule 4-3.3 on knowingly false statements of law; Rule 4-5.4 on independent professional judgment; and Rule 4-8.4 on conduct "prejudicial to the administration of justice".
It also points practitioners to the Office of Ethics Counsel informal opinion on attorney use of generative AI, Mo. Informal Op. 2024-11 of 25 April 2024, and encourages all attorneys practising in Missouri to be familiar with it.
Then it stops. A footnote states that the court "makes no decision regarding whether Conley's conduct violated any rule", and that the determination, and whether any violation warrants discipline, rests solely in the discretion of the Supreme Court of Missouri. Anyone reporting this as a disciplinary finding is reading something that is not there.
What the opinion does not do
It sets no rule about disclosing AI use, requires no certification, and imposes no filing procedure. Nothing in it changes what a Missouri filer has to put on the page. What changed is the reasoning a court applied to an existing certification rule.
It does not treat the apology as a defence. The court records that the response to the show cause order "was earnest and apologetic", and sanctions anyway, because the filing had already caused the court to order opposing suggestions.
It is also not a decision about AI in adjudication, judicial use of AI, or vendor tools. The subject is counsel's prefiling inquiry, and the sanction is a fee award, not a penalty paid to the court.
What we did not verify
What we opened: the six page typeset opinion in full, read as extracted PDF text, including the caption block carrying the filing date of 8 September 2026 and the docket number ED114731, the Rule 55.03(b) quotation, the two violation findings, the professional conduct passage and both substantive footnotes.
What we did not open: the Missouri Courts' own copy of this opinion, the underlying writ filings and the show cause order, the response counsel filed to it, Mo. Informal Op. 2024-11, and the authorities the opinion cites, including Kruse v. Karlen, Mata v. Avianca and State v. Coleman. We describe those only as this opinion describes them. The copy we read is the court's typeset PDF as archived in a public case database, and we link the copy we actually read rather than one we did not.
Quotations are reproduced with ASCII punctuation in place of the typographic quotation marks and apostrophes used in the typeset opinion, which is a house typesetting convention and not a change to any word.
What we refuse to claim: we do not say counsel has been disciplined or will be, because the opinion expressly leaves that to the Supreme Court of Missouri and makes no finding of a rule violation. We do not say the court prohibited or discouraged the use of generative AI, because it wrote the opposite. We do not describe the opinion as the first of its kind, in Missouri or anywhere, because it does not say so and we did not test it. We do not state whether the opinion is published, precedential or subject to rehearing or transfer, because we did not verify the court's designation.
Informational analysis for working professionals, not legal advice. Confirm how any rule applies to your situation with qualified counsel.
If you are writing a firm AI policy, this opinion argues for putting the obligation in the verification clause and not the tool-approval clause. The court's own analogy is to signing your name to work prepared by someone else without verifying the accuracy of the claims in it, which on our reading puts the defect in the signature rather than in the source of the draft. The court names no other source, and the extension is ours. A policy built around which tools are permitted answers a question this court says was incidental.
Source File
Open the opinion and confirm four things: the filing date of 8 September 2026 in the caption block, the Rule 55.03(b) quotation, the paragraph beginning "To be clear, this Court is not sanctioning Conley because she used generative AI", and the footnote stating that the court makes no decision on whether any rule of professional conduct was violated.
To be clear, this Court is not sanctioning Conley because she used generative AI. The use of AI is only incidental to the sanction. There is nothing inherently problematic from a briefing perspective with the use of generative AI. ยท State of Missouri ex rel. Schnell v. Richardson, No. ED114731, opinion filed 8 September 2026
FAQ
Was the attorney sanctioned for using AI?
No, and the court says so directly. It states that it is not sanctioning counsel because she used generative AI, that the use of AI is only incidental to the sanction, and that there is nothing inherently problematic from a briefing perspective with using it. The sanction is for filing pleadings citing cases that do not exist.
Then what made the conduct unreasonable?
The failure to check. The court treats generative AI's tendency to fabricate caselaw as well documented, and concludes that it is objectively unreasonable for any attorney or self-represented party to fail to verify AI's accuracy, adding that for this reason alone sanctions are appropriate.
Will the attorney face discipline?
The opinion makes no finding on that. A footnote states that the court makes no decision regarding whether the conduct violated any rule, and that the determination, and whether any violation warrants discipline, rests solely in the discretion of the Supreme Court of Missouri.
Does this create a new filing requirement in Missouri?
No. The opinion imposes no disclosure duty, certification or filing procedure. It applies Rule 55.03, which already required a reasonable prefiling inquiry, and the sanction is an award of $1,750 in attorney's fees to the petitioners in the underlying action.
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