Despite myriad possible differences in perspectives brought to an investigative interview by eyewitnesses and interviewers, little is known about how such differences might affect eyewitness memory reports or interviewer behavior. Two experiments tested the impact of such differences in a dynamic interaction paradigm in which participants served as eyewitnesses and interviewers. In Experiment 1 (N = 38 pairs), reporting goals for eyewitnesses and interviewers were manipulated in a factorial design, with participants instructed to provide or obtain either as much information as possible or only accurate information. Matching interviewer-interviewee instructions promoted accurate reporting, regardless of the actual content of the instructions. In Experiment 2 (N = 45 pairs), access to information about corroborating eyewitness identifications was manipulated in a factorial design. Corroborating information affected interviewers, but not eyewitnesses. When interviewers did not have access to corroborating information, they provided more negative feedback, and there was a trend toward interrupting more and asking more yes/no questions. These experiments indicate that differences in perspective can have effects on both the content of a witness's report and the behavior of an interviewer. The potential for differences in perspective should be considered in research on protocols intended to maximize eyewitness report accuracy.

Knowledge of task-irrelevant information influences judgments of forensic science evidence and thereby undermines their probative value (i.e., forensic confirmation bias). The current studies tested whether laypeople discount the opinion of a forensic examiner who had a priori knowledge of biasing information (i.e., a defendant's confession) that could have influenced his opinion. In three experiments, laypeople (N = 765) read and evaluated a trial summary which, for some, included testimony from a forensic examiner who was either unaware or aware of the defendant's confession, and either denied or admitted that it could have impacted his opinion. When the examiner admitted that the confession could have influenced his opinion, laypeople generally discounted his testimony, as evidenced by their verdicts and other ratings. However, when the examiner denied being vulnerable to bias, laypeople tended to believe him-and they weighted his testimony as strongly as that of the confession-unaware examiner. In short, laypeople generally failed to recognize the superiority of forensic science judgments made by context-blind examiners, and they instead trusted examiners who claimed to be impervious to bias. As such, our findings highlight the value of implementing context management procedures in forensic laboratories so as not to mislead fact-finders.

Abstract. Knowledge of task-irrelevant information undermines the probative value of forensic evidence (i.e., forensic confirmation bias). Cross-examination may sensitize jurors to bias – but do attorneys recognize when bias has tainted evidence against their client and adjust their cross-examination strategy accordingly? To address this question, 130 defense attorneys imagined representing a man charged with manslaughter and reviewed a case file that included, among other things, an autopsy report from a medical examiner who was either aware or unaware of their client’s recanted confession before ruling the death a homicide. When the examiner knew of the confession, attorneys rated the autopsy as no less probative or reliable, they were no less confident in their client’s guilt, and only 46% raised the possibility of confirmation bias on cross-examination. Our findings suggest that defense attorneys underappreciate the impact of forensic confirmation bias, such that biased forensic testimony would be better avoided via procedural reform.

Knowledge of task-irrelevant information undermines the probative value of forensic evidence (i.e., forensic confirmation bias). Cross-examination may sensitize jurors to bias—but do attorneys recognize when bias has tainted evidence against their client and adjust their cross-examination strategy accordingly? To address this question, 130 defense attorneys imagined representing a man charged with manslaughter and reviewed a case file that included, among other things, an autopsy report from a medical examiner who was either aware or unaware of their client’s recanted confession before ruling the death a homicide. When the examiner knew of the confession, attorneys rated the autopsy as no less probative or reliable, they were no less confident in their client’s guilt, and only 46% raised the possibility of confirmation bias on cross-examination. Our findings suggest that defense attorneys underappreciate the impact of forensic confirmation bias, such that biased forensic testimony would be better avoided via procedural reform.