The legal records pertaining to Johne McGill—also recorded as McGillis—of Prestonpans reveal a life profoundly marked by the judicial intensity of the late sixteenth century. His connection to the broader machinery of the Scottish witch trials was rooted in his family history; he was the son of Gilbert McGill, a man who had also been condemned and executed in Haddington. While archival evidence suggests that a Johne Makgill from Garvald was identified as a witchcraft suspect by the Haddington Presbytery as early as June 1588, the scarcity of surviving documentation makes it difficult to definitively confirm if this individual and the later subject are one and the same.
By May 1591, however, the legal proceedings against Johne reached a definitive conclusion. Following a trial conducted under the authority of the contemporary courts, he was found guilty of the charges brought against him. In accordance with the sentence delivered by the judiciary, Johne was executed. These records, preserved in the trial archives, remain the primary evidence of his final encounter with the Scottish justice system during a period of significant ecclesiastical and civil scrutiny.