The jury's rise as lie detector.

Author:Fisher, George



    1. Seeking Divine Sanction for Criminal Verdicts

    2. The Special Case of Capital Convictions

    3. The Reality Beneath the Illusion


    1. Curtains Open: The Seventeenth Century

    2. The Act To Abolish Hostilities with Scotland

    3. The Treason Trials and the Treason Act of 1696


    1. Witness Competency Rules and the Rule of Bethel's Case

    2. Empirical Interlude: Criminal Trials in an

      Eighteenth-Century Court

    3. Alibis and the Problem of Unavoidable Conflicts


    1. The Downfall of Witness Competency Rules in Civil Cases

    2. The Downfall of the Prohibition Against Defendant

    Testimony in Criminal Cases

    We say that lie detecting is what our juries do best. In the liturgy of the trial, we name the jurors our sole judges of credibility and call on them to declare each witness truthteller or liar.(1) All hierarchies of rank, learning, and technical prowess give way in the face of this asserted power of common jurors to spot a lie: In most jurisdictions today, no trial judge may advise the jury that a witness has lied.(2) No psychiatric expert may comment on a witness's credibility(3) Rarely may a polygraph technician lecture to jurors about a witness's pulse and pressure, tension or temperature.(4) The job of lie detecting belongs to the jurors alone. Nor may we later, once the jurors have done their job of sifting truth from falsehood, review how they did it. In a trial process in which we hide so much of the law and evidence from the jurors, this they hide entirely from us.

    We do not leave our jurors wholly unequipped for this task of lie detecting. They come to court, as we so often tell them, with their common sense and may reject any evidence that defies it. Inside court, we give them three more lie-detecting tools: the oath, demeanor evidence, and cross-examination. Every witness must promise to tell the truth, face the jurors for their scrutiny, and endure the challenge of opposing counsel. If these tools are lacking, we do not put the jury to the task of detecting lies. Hence we usually do not ask jurors to judge the truthfulness of an out-of-court witness. But this general bar against hearsay is our only broad exception to the otherwise unqualified rule that leaves questions of credibility to the jury.

    Of course, many cases impose no particular burden on the jury's powers to ferret out lies. In many cases there is no conflict in testimony. In many others there is a conflict, but the jury is able to attribute it to mistake or misperception or memory loss. In many cases, however, two witnesses tell two stories that cannot innocently be reconciled. Here the jurors must call someone a liar--indeed they must call someone a perjurer. Still, at least in civil cases, in which the jurors must merely say which witness was more truthful, their task remains relatively simple. Criminal cases mount a starker challenge. If the defendant has taken the stand to refute the testimony of a prosecution witness, then the jury may not convict unless it is prepared to credit the accuser's testimony over the defendant's and to do so beyond a reasonable doubt. To be sure, it is not wildly uncommon for defendants to proclaim their innocence in the face of a freight train of evidence--and when they do, jurors may readily brand them perjurers as well as thieves. But there are many criminal cases in which we give the jurors no substantial evidence other than the oath of the accuser and the oath of the accused. In such cases, we put jurors to the intractable task of searching the faces and gestures of strangers for the signs of deceit.

    Our unguarded confidence that jurors are up to this task is the more remarkable for being so probably wrong. There is little evidence that regular people do much better than chance at separating truth from lies. We tend to rely on worthless clues and to misread others.(5) But although the jury does not guarantee accurate lie detecting, it does detect lies in a way that appears accurate, or at least in a way that hides the source of any inaccuracy from the public's gaze. By permitting the jury to resolve credibility conflicts in the black box of the jury room, the criminal justice system can present to the public an "answer"--a single verdict of guilty or not guilty--that resolves all questions of credibility in a way that is largely immune from challenge or review. By making the jury its lie detector, the system protects its own legitimacy.

    This error-erasing function of jury lie detecting disables other mechanisms that are supposed to guard against wrongful verdicts. It relieves both judge and prosecutor of their usual charge to evaluate the evidence before passing the case to the jury. At the motion for directed verdict, which is usually a chance for the trial judge to rid the system of a flimsy prosecution, the judge simply assumes the truthfulness of the government's witnesses and leaves the problem of lie detecting altogether to the jury.(6) Appellate courts refuse to revisit the jury's judgments of credibility. And prosecutors, who normally must assure themselves that they have probable cause to bring charges, are able to avoid any meaningful duty to screen out weak cases when guilt turns on a question of credibility. The sworn testimony of a named witness who is not obviously delusional is all the prosecutor needs to satisfy probable cause.(7)

    In the pages ahead I want to search out the source of this quiet confidence that the jury can answer all credibility questions. When and why did the system declare that jurors had the wisdom to arbitrate unvarnished credibility conflicts at criminal trials? To the question "when," the surprising answer is very recently. If we walk back a mere 140 years through the nearly 800-year history of the criminal trial jury, we find ourselves at a time when no jury had to choose between the sworn testimony of accuser and accused at a criminal trial. Not until the second half of the nineteenth century could accused criminals anywhere in the common law world testify under oath at their own trials. Defendants could tell their stories, but they could not swear to them, and a jury tom between two conflicting stories could choose simply to credit sworn accusation over unsworn denial.

    If we walk back another 160 years, we arrive at a time when no jury had to choose between the sworn testimony of prosecution and defense witnesses at a serious criminal trial. Not until the turn of the eighteenth century could accused felons call sworn witnesses. They could call unsworn witnesses, but a jury in doubt could simply prefer the sworn evidence. Walking back 150 more years, to the middle of the sixteenth century and before, we come to a time when only the prosecution could present any sort of witness at a criminal trial. Although defendants could speak, they were not sworn, and they could call no witness to speak for them. The juries that presided over the rump trials of these early years faced nothing like our modern conflicts of oaths.

    This thumbnail history suggests that the "why" question is somewhat more complicated than we might have anticipated. Before we can inquire why the system gave the jury the unbounded discretion to resolve credibility conflicts between sworn witnesses, we must first examine why the system in its early days sought to avoid such credibility conflicts altogether. The answer to both questions, I will argue, turns on the system's need for legitimacy--for public confidence in the accuracy of its outcomes.(8) In the early years of the criminal trial jury, the system sought to stake its claim to legitimacy primarily in the oath and in the perceived divine power of the oath to compel truthful testimony. The oath's central role demanded that the system avoid sworn credibility conflicts, because any such conflict would reveal in a visible and obvious way the oath's inadequacy to assure truthful testimony. Hence when the system first permitted conflicts in testimony to emerge, it did not permit sworn conflicts.

    This and other contrivances to avoid conflicts in oaths permitted the system to embrace an evidentiary presumption that all sworn evidence was truthful--a presumption that sounds distinctly alien to us, yet persisted in stronger or weaker form throughout much of the jury's history. In time, however, for masons I will discuss later, the system gradually had to release its grip on the oath as a source of legitimacy. As it did, it turned to the jury as an alternative. During the last several centuries of the jury's history, the system has committed ever more--and more intractable--credibility conflicts to the jury's black box. And the jury, in loyal support of the system's legitimacy, has issued crisp and impregnable verdicts.

    This Article tells the long story of the jury's slow coming of age as the system's lie detector at criminal trials. It chronicles the deaths of the old evidence rules that effectively withheld from the jury the task of settling credibility conflicts between sworn witnesses. Like the characters of many good stories, these rules led uneventful lives but suffered noteworthy deaths, touched by the intrigue of treachery and factional strife. I will emphasize two features of the evolutionary process. First, it was astoundingly slow. Despite the jury's attractiveness as a means of resolving credibility conflicts, the system displayed a remarkable resistance to change, an inertia of planetary proportions disturbed only by explosive events. Second, the most important of these explosions were external to the system. As a result, the evolutionary process was not principled, driven by a conviction that the jury can and should resolve credibility conflicts. Instead, the rule changes that most greatly expanded the potential for sworn credibility conflicts at criminal trials were products of...

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