A look at expert testimony on false confessions

In 2002, Bradlee Marsh picked up brothers Jonathan and Anthony Boyer as they walked along a roadway in Louisiana. Marsh would not leave his truck alive. After robbing and killing him, Jonathan Boyer fled to Florida, where officers found him walking down a street. When Boyer allegedly attempted to free a gun from his waistband, Sergeant Guy Weber fired two shots. Though he missed Boyer, Weber was able to capture and take him into custody. After a two-hour interrogation, Boyer confessed to police. Seven years later, a Louisiana jury convicted Boyer of this crime — armed robbery and second-degree murder — basing its decision primarily on his confession and the testimony of his brother, Anthony.

In his appeal, Boyer cited several errors, including infringement of his rights to a speedy trial and the exclusion of expert testimony from an expert regarding the psychological underpinnings of false confessions. The U.S. Supreme Court will consider both potential errors this spring in the case Boyer v. Louisiana. The issue of false confessions has important implications for psychologists. Despite the lower courts' rulings that Boyer voluntarily confessed to the murder, his appeal raises questions as to the validity of the confession.

For example, Jonathan claimed that Anthony, "a vicious drunk who savagely assaulted his wife," killed Marsh. Yet Anthony testified against his brother at trial with immunity. Jonathan Boyer also claimed that his prior mental health problems decreased his ability to make a fully informed confession. Finally, Jonathan Boyer claimed that being shot at by Weber frightened him, which disrupted his ability to think clearly. After confessing, Jonathan Boyer was placed on suicide watch, perhaps lending credibility to this claim. Given the dubious legitimacy of Boyer's confession, the excluded psychological testimony from Solomon Fulero, PhD, JD, regarding the nature of false confessions may have shed light on the truth of Boyer's mindset. The Supreme Court will address whether barring such testimony violated the defendant's 6th Amendment due process rights and ability to present an adequate defense.

Although false confessions amount to approximately 25 percent of wrongful convictions and are highly persuasive to jurors, Louisiana is not the only state that either prohibits or makes it legally difficult to admit expert testimony on factors that increase the likelihood of false confessions. Courts often exclude expert testimony regarding false confessions based on the nebulous and under-scrutinized notion that this testimony "invades the province of the jury." Further, courts often believe that jurors are able to determine the validity of a confession on their own without expert testimony, and that juries will not greatly benefit from expert testimony.

To the first point, 2005 research by Saul Kassin and colleagues contradicts the notion that jurors can spot a false confession when they see one. In one study, Kassin and colleagues videotaped prisoners' true confessions to their actual crimes and false confessions to a fabricated crime. Overall, both undergraduates and police had difficulty determining which of the confessions was true and which was false. Further, although jurors can identify coerced confessions, these confessions still affect their decisions by increasing conviction rates (Kassin & Sukel, 1997). As a result, many in psychology and law believe that expert testimony on false confessions can educate and sensitize the jury to these factors and ultimately produce fairer legal outcomes.

Boyer v. Louisiana highlights the importance of expert testimony on false confessions. By allowing such expert testimony, the Supreme Court could affect how trial courts view the testimony of experts on other related issues, such as lineup identification and investigative interviewing practices. Researchers in psychology and law can assist courts by defining and clarifying the probative and prejudicial nature of this testimony, and create guidelines to assist judges in their gatekeeper role in deciding the admissibility of such evidence.

"Judicial Notebook" is a project of APA's Div. 9 (Society for the Psychological Study of Social Issues).