False Confessions, True Confessions, and the Q Factor

EXHIBIT A Steven A. Drizin and Richard A. Leo, The Problem of False Confessions in the Post-DNA World, 82 N.C. L. Rev. 891, 930-31 (2004) In this Article, we analyze 125 recent cases of proven interrogation-induced false confessions (i.e., cases in which indisputably innocent individuals confessed to crimes they did not commit) and how these cases were treated by officials in the criminal justice system. ... This is ... the largest cohort of interrogation-induced false confession cases ever identified and studied in the research literature. ... [T]here is no existing universe or database of police interrogation cases from which researchers would be able to draw a random sample. Moreover, even if such a database existed, it would make as much sense for someone studying the causes and consequences of interrogation-induced false confessions to randomly sample police interrogations as it would for someone studying the causes and consequences of lung cancer to randomly sample healthy individuals. The appropriate universe of cases for this study is interrogation-induced false confessions, not all police interrogations.

EXHIBIT B Neil A. Accortt et al., Chronic Disease Mortality in a Cohort of Smokeless Tobacco Users, 156 Am. J. Epidemiology 730 (2002) Our aims are to assess the potential increased mortality risks associated with smokeless tobacco use in a representative sample of the US population and to evaluate the effects of the combined use of smokeless tobacco and cigarette smoking on mortality from chronic diseases. ... We used data from ... a national probability sample of the noninstitutionalized US population ... . After adjustment for age, race, gender, and poverty status, ... [f]emale smokeless tobacco users experienced an increase in mortality from all cancers ... of borderline significance. ... Male exclusive smokeless tobacco users did not experience significant increases in mortality for any type of cancer considered. ... [T]he lung cancer mortality among combined users was nearly twice that of exclusive smokers. ... .

The study of false confessions described in Exhibit A is important and influential. There is much to be said for detailed, historical studies of miscarriages of justice. Analyzing what went wrong in a series of cases can suggest possible reforms to prevent or abate these outcomes in the future.

But by design, the study is not capable of determining the causes of any of the confessions of the 125 DNA-exonerated men. It is comparable to a series of medical case reports rather than to an epidemiological study, such as the one in Exhibit B, which is designed to detect a possible risk factor or cause of cancer. Physicians may report on unusual and interesting cases in which a disease follows an exposure to some factor, such as lung cancer after years of smoking. But without data on the incidence of lung cancer among nonsmokers (or relevant experiments on the effects of smoking), how can one conclude from the study that smoking causes (or even is risk factor for) cancer? A case series offers almost nothing in the way of proof of causation. The persuasive evidence that smoking causes cancer came from large case-control and cohort studies in several populations—not from the earlier case series.

Confronted with defendants' efforts to introduce the testimony of psychological experts on the factors found to be present in DNA exonerations, prosecutors have harped on this point. They have argued that although factors such as physical isolation and extended interrogation sessions certainly can contribute to false confessions, they may also contribute to true confessions, and there is no proof that they are more likely to contribute to a false confession than a true one. In other words, a factor may be relevant to voluntariness—whether the defendant’s will was overborne by unfair pressure—but not be evidence of falsity.

Several courts have agreed that the proffered risk factors are not adequately linked to false as opposed to true confessions.  One federal district court rebuffed defendant’s risk-factor testimony as “nothing more than guesswork: coercive interrogation techniques may lead to false confessions but also produce true confessions, and such techniques were used in this case ... .” United States v. Deuman, 892 F.Supp.2d 881, 888 (W.D. Mich. 2012). The Michigan Supreme Court ruled that the research was methodologically flawed for “failing to compare true and false confessions and identify factors that contribute to false confessions but not true confessions.” People v. Kowalski, 821 N.W.2d 14, 22 (Mich. 2012). Likewise, the Supreme Judicial Court of Massachusetts found it telling that the expert “acknowledged that no studies have been conducted comparing the prevalence of these factors among false confessions to either ‘true’ confessions or all confessions” and “that the studies based on proven false confessions that have been used to identify these relevant factors were based on a sample size of approximately 150 to 200 proven false confessions.” Commonwealth v. Hoose, 5 N.E.3d 843, 861 (Mass. 2014).

These criticisms, I believe, are valid—but only as applied to a possible effort to define a false-confession “profile” or to conclude that when the putative risk factors are present, a confession is false. Defense experts in these cases do not pretend that they can diagnose whether a confession is true or false.  They simply want to present information that they are convinced will help the jury make this judgment. And their beliefs about causes and risk factors for false confessions are based on a richer set of studies than just the case reports.

Consequently, the opinions summarily dismissing all false-confession research as scientifically flawed because of the lack of a comparison group in studies like the one in Exhibit A are too hasty. Furthermore, the testimony could serve a function other than telling the jury which factors are relevant to concluding that a confession is false (for which data on causation or correlation is essential). Suppose that research reveals a factor—I will call it factor Q—that makes virtually every innocent suspect confess. Moreover, although there are no data directly on point, it is highly plausible that Q would have the same effect on guilty suspects. Because the probability of a confession conditional on Q is very large for both innocent and guilty suspects, the relative risk is close to 1. Q is not indicative of whether a given confession is true or false.

Nonetheless, informing the jury of the factor and its impact on innocent defendants could be helpful (if the jury would not otherwise recognize the presence and significance of Q). The point of this testimony would not be to prove that Q has probative value in distinguishing between true and false confessions. It would be show that the confession in the case lacks the probative value that the untutored jury might attribute to it.

Rather than issuing sweeping denunciations of the entire body of psychological research into false confessions as methodologically sterile, courts should focus on whether the expert testimony exceeds the bounds of valid generalizations from the research and how much the particular testimony really can assist the jury. Are there powerful factors like Q that the jury would not recognize? I cannot say that I know the answer, but it is a fair question.

Acknowledgments: Thanks to Debbie Davis and Tom Workman for correspondence on the logic of "risk factors" for false confessions. A longer discussion of the admissibility of expert testimony on false confessions will appear in the 2015 Cumulative Supplement to The New Wigmore: A Treatise on Evidence.