On 15 May 1440, Rais kidnapped a cleric during a dispute at the Church of Saint-Étienne-de-Mer-Morte. The act prompted an investigation by the Bishop of Nantes, during which evidence of Rais' crimes was uncovered. On 29 July, the Bishop released his findings, and he subsequently obtained the prosecutorial cooperation of Rais' former protector, John VI, Duke of Brittany. Rais and his bodyguards Poitou and Henriet were arrested on 15 September 1440, following a secular investigation that corroborated the Bishop's. Rais' prosecution was likewise conducted by both secular and ecclesiastical courts, on charges that included murder, sodomy and heresy.