The prosecutors were John Humffreys Parry and William Jerome Knapp; Hopley was defended by the serjeant-at-law William Ballantine, who subsequently described Hopley as "distorted". Throughout his trial, Hopley described himself as reluctant to use corporal punishment. In describing the events preceding Cancellor's death, Hopley stated that he started crying while beating Cancellor, after which Cancellor presented his lesson and "Hopley took his head on his breast and prayed with him". Hopley presented testimonials from past students who described him as "kindly" and who noted an infrequent use of violence. Hopley claimed to be a paedagogical follower of John Locke, who had decried the use of corporal punishment except in cases of extreme obstinacy on the part of the student. He argued that, through the application of this theory, the beating that killed Cancellor had been a necessary one. Robert Willis testified at the trial that there was no possibility that Cancellor's death had been a result of natural causes. He presented a detailed description of the boy's injuries, suggesting that they had been sustained over several hours. He also revealed that Cancellor's skull cavity contained six to eight ounces of fluid, attributing to this fluid the boy's seeming inability to learn as described by Hopley, but rejected any suggestions that it may have contributed to Cancellor's death. Cancellor's brother, Fowler, and Locock all testified against Hopley; Locock's testimony was particularly hostile, suggesting that Hopley's incompetent response to interviews was "tantamount to an admission of guilt". Other witnesses included the Hopleys' laundress, Roberts, three members of the coastguard who had seen lights on in the house late at night, a local constable, and the town registrar. Ballantine's conduct during the trial was flawed, and he believed Hopley was insane. Although he promoted the testimonials of former students and argued that a schoolmaster was unlikely to "so lightly jeopardize his ambitions", he congratulated Locock on the accuracy of his testimony in open court. Ballantine did not call key witnesses such as Edward Philpott, another student of Hopley's who had been at the house that night. Philpott slept in the bedroom beside Cancellor's and had reported hearing no unusual noises or screams from Cancellor's room on the night of his death. Neither did Ballantine call Professor John Eric Erichsen of University College Hospital, who had conducted a second autopsy on Cancellor on 11 May and suggested that "the misleading appearance of the body