When in 1684 Henry Viscount St John was convicted of killing Sir William Estcourt in a brawl, and Charles II used the royal prerogative for his pardon, Bishop Barlow published an elaborate tract (1684–1685) in support of regal power to dispense with penal laws. This was succeeded by "a case of conscience", proving that kings and supreme powers had authority to dispense with the positive precept condemning murderers to death. In the same year (1684), as the persecutions of nonconformists increased in violence and the quarter sessions of Bedford published "a sharp order" enforcing strict conformity, Barlow issued a letter to the clergy of his diocese requiring them to publish the order in their churches. A "free answer" was written to this letter by John Howe.