An appeals court judge in Brazil left an AI-chatbot prompt in his decision to acquit a 35-year-old man of the rape of a 12-year-old child in the state of Minas Gerais, Brazil.

The trial, which acquitted the the girl's mother of omission by a majority vote by a panel of judges, took place on February 11, 2026. Brazilian law considers it statutory rape when the victim is under 14 years of age, regardless of any consent from the victim or their parents, although similar rulings have occurred before in the country.

Núcleo obtained the full text of the ruling, which is sealed due to the sensitivity of the matter. On page 45, Judge Magid Nauef Láuar appears to have accidentally left in what seems to be a copy-and-paste from an AI chatbot — "Now improve the exposition and reasoning of this paragraph" — followed by the text he wanted ti refine.

The text snippet from the AI chatbot

The snippets below were translated from Portuguese and slightly adapted. See notes in the end for legal clarification.

JUDGE'S PROMPT:

Now improve the exposition and reasoning of this paragraph:

"Notwithstanding the defense arguments regarding insufficient evidence of omissive conduct on the part of the mother and the exclusion of culpability due to mistake of law, the fact that the material atypicality of the accused [initials suppressed by Núcleo], the first appellant, was recognized and his acquittal declared for lack of just cause, also warrants dismissing the criminal conduct attributed to the second appellant, notably because one cannot speak of a breach of the duty of guarantor when the typicality of the acts described in the initial charging document has been ruled out."

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AI OUTPUT:

"Notwithstanding the defense arguments articulated regarding insufficient evidence of the alleged omissive conduct attributed to the mother, as well as the application of an exclusion of culpability grounded in mistake of law, the recognition of the material atypicality of the conduct attributed to the accused [initials suppressed by Núcleo], the first appellant, with the consequent declaration of his acquittal for lack of just cause, projects necessary effects onto the charges brought against the second appellant."

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Editor's notes:

  • "Material atypicality" (atipicidade material) means the court found the defendant's conduct did not meet the legal definition of a crime.
  • "Exclusion of culpability due to mistake of law" (escusa de culpabilidade por erro de proibição) is a defense arguing the accused genuinely did not know their conduct was illegal.
  • "Duty of guarantor" (dever de garante) refers to the legal obligation of a parent or guardian to protect a minor from harm.

According to the Minas Gerais Court of Justice's website, in addition to its own AI solutions, access to Gemini and NotebookLM is also available through Google Workspace subscriptions. There is a “primer” section that warns of the need for human supervision and raises concerns about data protection

Resolution Nº. 615 of the National Council of Justice, which oversees the judicial branch and regulates the use of AI, states that judicial proceedings should not use tools "to process, analyze, generate content, or support decisions based on documents or data that are confidential or protected by judicial secrecy, under the terms of applicable legislation, except when duly anonymized at source or when technical and procedural mechanisms are adopted that guarantee the effective protection and security of such data and its subjects."

It's important to highlight this matter because a statutory rape case is automatically placed under judicial seal, in order to protect the victim and prevent any risk of their information being exposed.

Núcleo found no other passage containing an explicit AI prompt, nor did it run the document through AI detection tools — both because such tools are unreliable and because the ruling contains sensitive information that could identify the parties involved, given the uncertainty around how these models store and process such data.

The National Council of Justice requested clarification from the judge regarding the acquittal of the accused rapist. The council did not say in a statement whether the use of AI in the text would also be investigated.

Núcleo contacted the press office of the Minas Gerais Court of Justice regarding the use of artificial intelligence, the existence of internal rules governing its use, and questioned which parts of the text were submitted to the AI tool given the ruling's confidentiality

After the publication of the report in Portuguese, the press office reiterated the National Council of Justice's rules, but did not answer the other questions.

Read the full statement from the Minas Gerais court

The Minas Gerais Court of Justice informs that the use of artificial intelligence tools in its offices complies with the guidelines established by Resolution 615/2025 of the National Council of Justice.

Internally, TJMG has promoted educational and informational initiatives on this topic, such as a podcast on the subject (https://www.tjmg.jus.br/portal-tjmg/informes/uaicast-sobre-inteligencia-artificial.htm), and training and courses for magistrates, advisors, and civil servants, with guidance on the functioning of these technological resources and their ethical, transparent, and secure use, in which human supervision is indispensable.

Information about the use of Artificial Intelligence at the TJMG is available at https://www.tjmg.jus.br/portal-tjmg/institucional/inteligencia-artificial/atendimento-humanizado.htm.

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This story was originally published in Portuguese and translated with the help of artificial intelligence, with close review by humans editors, according to Nucleo's AI use policy.
Report Jeniffer Mendonça
Artwork Aleksandra Ramos
Editing Alexandre Orrico
Translation Sofia Costa