Evidence was given on May 29th, 1603, by three witnesses, one of whom was Margaret herself. She said she had been accustomed to mind cattle in the company of the boy, Jean Grenier, and that he had often frightened her by telling her horrible tales about being able to change into a wolf whenever he wished, and that he had killed many dogs and sucked their blood, but that he preferred to devour young children. He said he had recently killed a child, and after eating part of her flesh had thrown the rest to a companion wolf.
Margaret described the beast which had attacked her as stouter and shorter than a real wolf, with a smaller head, a short tail, and reddish hide. After she struck at it, the animal drew back and sat down on its haunches like a dog, at a distance of about twelve paces. Its look was so ferocious that she ran away at once.
The third witness was Jeanne Gaboriaut, who was eighteen years old. She gave evidence that one day, when she was tending cattle in company with other girls, Jean Grenier came up and asked which was the most beautiful shepherdess amongst them. Jeanne asked him why he wanted to know. He said because he wished to marry the prettiest, and if it was Jeanne he would choose her.
Jeanne said, "Who is your father?" and he told her that he was the son of a priest.
Then she replied that he was too dark in appearance for her taste, and when he answered he had been like that for a long time, she asked him whether he had turned black from cold or whether he had been burnt black.
He said the cause was a wolf's skin he was wearing, which had been given to him by one Pierre Labourant, and when he wore it he could turn into a wolf at will or any other animal he preferred, and he went on with details similar to those he had disclosed to Margaret Poiret.
It was proved, however, that Grenier was not the son of a priest, but of a labourer, Pierre Grenier, and that he lived in the parish of St. Antoine de Pizan.
When questioned as to his crimes, he confessed to the assault upon Margaret Poiret as described by her, and also that he had entered a house in the guise of a wolf, and finding no one there but a babe in its cradle he seized it by the throat and carried it behind a hedge in the garden, where he ate as much of the body as he could and threw the remainder to another wolf.
At St. Antoine de Pizan he attacked a girl in a black dress who was tending sheep, and he killed and devoured her, a strange point being that her dress was not torn, as happens in the case when real wolves make the assault.
When questioned as to how he managed to turn into a wolf, he said that a neighbour, called Pierre la Tilhaire, had introduced him in the forest to the Lord thereof, who had given wolf-skins to both, as well as a salve for anointing themselves. When asked where he kept the skins and the pot of ointment he replied that they were in the hands of the Lord of the Forest, from whom he could obtain them whenever he wished.