In the history most often told, the criminal trial jury has steadily surrendered power and prerogative. First cast as a group of roving decisionmakers without real judicial oversight, the jury gave up its lawmaking portfolio to judges, who then crabbed its factfinding mission as well. Professor Fisher tells a contrary history that focuses on the jury's expanding role as judge of witness credibility. In the jury's early centuries, the system put its faith not in the power of the jury to detect lies, but in the power of the oath to guarantee truthful testimony. An elaborate scheme of evidence rules promoted and protected the illusion that the oath assured truth. Gradually, as these old evidence rules fell away, the Anglo-American criminal trial jury assumed its full and formal status as our system's lie detector. At times, this process of legal change crossed paths with other larger events. The treason trials of late-Stuart England helped to speed the collapse of one old evidence rule. The bitter fight over the right of African Americans to give evidence in post-Civil War America helped to bring down another But beneath these tumultuous events coursed a broader systemic impulse that carried the jury forward toward its modem role as lie detector This impulse, Professor Fisher argues, was the system's need to protect the apparent legitimacy of its verdicts. For this task, the jury's ability to shroud all shortcomings within the black box of the deliberation room had an irresistible allure.
