Confessions That Corrupt

Abstract

Basic psychology research suggests the possibility that confessions-a potent form of incrimination-may taint other evidence, thereby creating an appearance of corroboration. To determine if this laboratory-based phenomenon is supported in the high-stakes world of actual cases, we conducted an archival analysis of DNA exoneration cases from the Innocence Project case files. Results were consistent with the corruption hypothesis: Multiple evidence errors were significantly more likely to exist in false-confession cases than in eyewitness cases; in order of frequency, false confessions were accompanied by invalid or improper forensic science, eyewitness identifications, and snitches and informants; and in cases containing multiple errors, confessions were most likely to have been obtained first. We believe that these findings underestimate the problem and have important implications for the law concerning pretrial corroboration requirements and the principle of "harmless error" on appeal.

Why confessions trump innocence.

“…The basic and forensic psychology research described above suggests the possibility that confessions have the power to corrupt other evidence, further enhancing its impact on judges and juries. To determine if this phenomenon, amply demonstrated in the laboratory, also occurs in actual cases, Kassin, Bogart, and Kerner (2012) conducted an archival analysis of DNA exonerations from the Innocence Project case files. To test the "corruptive confessions" hypothesis, they compared the number and kind of errors made in wrongful conviction cases containing a false confession with those in which there was no confession.…”

False Memories

“…Unfortunately, as is often true in cases of false confession (where a person confesses to a crime he did not commit), the confession is so powerful that it contaminates how the other pieces of evidence are evaluated (Kassin et al, 2012). It became clear to many that the details were too outlandish, and the discrepancies too large to be believed.…”

Will jurors correct for evidence interdependence in their verdicts? It depends

“…Although the legal system operates under the assumption that each piece of evidence furnished in a trial is independent and not tainted by any other piece of evidence, research shows this is not always the case. There has been a recent increase in research examining how various pieces of evidence have the potential to contaminate one another in the investigatory stage (e.g., Hasel & Kassin, 2009;Kassin, Bogart, & Kerner, 2012) because criminal investigators rarely make judgments in contextual isolation and generally view each piece of evidence in relation to other information pertaining to the case (Ask, Rebelius, & Granhag, 2008). Experimental studies that have systematically varied the evidence provided to investigators (e.g., Ask et al, 2008;Charman, Gregory, & Carlucci, 2009), forensic scientists (e.g., Dror & Charlton, 2006;Dror & Rosenthal, 2008), and sources of person-evidence, such as eyewitnesses (e.g., Hasel & Kassin, 2009) or alibi corroborators (e.g., Marion, Kukucka, Collins, Kassin, & Burke, 2016), support this conclusion.…”

“…An analysis of the first 241 Innocence Project exonerations showed that 54.58% of cases had multiple errors listed that contributed to the wrongful convictions (Kassin et al, 2012), which suggests that evidence collected early in an investigation could potentially contaminate later pieces of evidence in a multitude of ways. The forensic confirmation bias proposes pre-existing beliefs or knowledge of early evidence can impact the way legal decision-makers gather and evaluate evidence, determine whether and how to proceed to trial with that evidence, and present the information to triers-of-fact in court (Kassin, Dror, & Kukucka, 2013).…”