As archdeacon at Turin he was a member of the commission appointed by Pope Clement VIII to edit the Liber Septimus decretalium (later known as the Constitutiones Clementinae); and he also wrote Paratitla on the five books of the Decretals of Gregory IX.
Called "subtillissimus canonum doctor/a most subtle teacher of canon law" by Tommaso Diplovataccio, John was the compiler of a fine commentry on decretals.