Sanction teardown · Parana State, Brazil · 2025-04-11
Vilmar Martins dos Santos v. State of Parana
What happened
In Parana State, Brazil, a filing relied on an unnamed/unconfirmed AI tool to help draft legal argument. The court identified the following problems with the citations in that filing:
-
False Quotes (Exhibits & Submissions)Defense attributed a phrase to the pronúncia that the court states does not exist in that decision.
-
False Quotes (Exhibits & Submissions)Defense inserted a conclusion as if from the pronúncia; the court confirms the phrase is not present.
-
Fabricated (Case Law)Fabricated TJPR decision using an implausible process number pattern; court says the jurisprudence is AI-created.
-
Fabricated (Case Law)Fabricated TJPR decision naming a non-existent desembargador in the country.
-
Misrepresented (Case Law)Fabricated TJPR decision listing João Pedro Gebran Neto as TJPR relator; court notes he belongs to TRF-4, not TJPR.
-
Fabricated (Case Law)Fabricated TJPR decision with a relator name the court says does not exist.
-
Fabricated (Case Law)Fabricated TJPR appeal citing a non-existent desembargador as relator.
-
Misrepresented (Case Law)Misrepresented TJPR decision naming a judge who had retired long before the cited dates.
-
Fabricated (Case Law)Fabricated STF habeas corpus; court states none of the STF citations listed are genuine.
-
Fabricated (Case Law)Fabricated STJ habeas corpus; court states none of the STJ citations listed are genuine.
-
Fabricated (Case Law)Fabricated STJ interlocutory agravo in special appeal; court found STJ citations not authentic.
-
Fabricated (Case Law)Fabricated STF agravo de instrumento; court indicated STF citations were not genuine.
-
Fabricated (Case Law)Fabricated TJPR decision again using implausible numbering pattern and a non-existent relator.
Which AI tool
an unnamed/unconfirmed AI tool. Note: Charlotin's public database records tool attribution only where a court order, brief, or reporting on the matter states it explicitly; "unidentified" or "implied" means the record indicates AI use but does not name a specific product — we do not guess.
Outcome
Appeal dismissed; lawyers warned
How Citation Safe would have caught this
Citation Safe runs three deterministic layers before a brief is filed: (1) does the citation exist against CourtListener's database of published opinions, (2) if quoted, does that exact language appear in the source, (3) does the cited case actually support the proposition it is cited for. Fabricated case citations fail Layer 1. Fabricated or misattributed quotations fail Layer 2 even when the underlying case is real. Misrepresented holdings — a real case cited for a proposition it does not support — are the target of Layer 3. None of these checks involve asking another language model whether the citation looks right; they are lookups and text-matches against the actual source, which is why a hallucinated citation has to survive a direct lookup against the authoritative source — not another model's opinion — to earn a VERIFIED stamp; our measured false-verify rate is published live at /quality.
Check a brief before you file it → · See our live false-verify rate
Source: https://www.damiencharlotin.com/documents/481/Vilmar_Martins_dos_Santos_v._State_of_Parana_Brazil_11_April_2025.pdf, via Damien Charlotin's public AI Hallucination Cases Database (CC0).