Unlike her older sister, Olympe, comtesse de Soissons, who was forced to flee to Liège and later to Brussels, in order to escape arrest, Marie Anne was never formally convicted. The trial against her was conducted 29 January 1680, and she appeared escorted by her husband and her lover Vendôme holding each of her arms, and stated that she did not accept the authority of the court and had accepted to answer the court summon only out of respect for the king's rank. She claimed that she and Vendôme had merely expressed a wish of frivolity, a joke, harmless and not honestly intended, to Lesage, and that if they believed that she had the wish to murder her husband, they could ask him if he thought so, as he had accompanied her to the trial.