Catharin Mactargett, a married woman of middling status living in Dunbar, Haddington, first entered the purview of the Scottish legal system in 1679. During the Haddington circuit court proceedings of that September, she was cited on a Porteous roll alongside others facing charges of witchcraft, sorcery, necromancy, and the total renunciation of their baptism to the Devil. Rather than face these serious allegations, Catharin chose to flee, resulting in her being declared a fugitive. Despite this attempt to evade the law, she eventually appeared before a commission of justiciary in 1688, where her history as a "known witch"—a reputation reinforced by testimony from Margret McClean and Annabell Stewart in other trials—was brought to bear against her.
While records note that Catharin and her husband, a weaver, possessed an adequate income, she faced accusations of having been a beggar, a charge that often intersected with tensions surrounding local poverty and social reputation. By May 1688, she was held in the Tolbooth, where she provided a confession on the 19th of the month. The dittays against her were extensive, encompassing broad allegations of harm to the local economy and domestic life, including the destruction of ale, the ruination of entire dairies, the death of animals, and the eventual ruin of whole estates. Following her 1688 trial in Haddington, the court reached a verdict of guilty, concluding a protracted legal struggle that had shadowed her for nearly a decade.