In early modern French legal culture, interdiction was a procedure through which someone could be proven incapable of managing his fortune, because of “fury, imbecility, or prodigality”. Legal interdiction necessitated the choice of a curator to take charge of the insane person’s financial interests while he was confined, either by his family or in a private or royal place of detention in mainland France. Aimed at protecting both the mad person and his family, interdiction had in practice both civil and penal consequences. In order to secure the interdiction of a relative, families had to build up cases to justify such legal decisions, which had to be based on petitions, witness testimony and the interrogation of the person in question by a magistrate, as well as a family assembly. This chapter is based on the study of 40 cases of interdiction of free men by judges in Saint-Domingue. Their interrogations are especially interesting to furthering our understanding of which kinds of behavior were considered intolerable in a colonial context and how they came to be characterized as mad.