Father Ambrose appeared before the presiding judge, Sir Robert Heath, on 7 September when he professed his adherence to the Catholic faith and defended his actions. On 8 September, the feast of the Nativity of Mary, Sir Robert Heath found Ambrose guilty and sentenced him to be executed. Two days later, he was taken from Lancaster Castle, drawn on a hurdle to the place of execution, hanged, dismembered, quartered, and boiled in oil. His head was afterwards exposed on a pike.