The presumption of guilt in suspect interrogations: Apprehension as a trigger of confirmation bias and debiasing techniques.

Abstract

This research tests whether a police officer's decision to apprehend a suspect triggers confirmation bias during an interrogation. The study also tests two strategies to reduce confirmation bias: (1) decoupling decision to apprehend from interrogation and (2) reducing cognitive load for the interrogating police officer. In Experiment 1, Swedish police officers (N = 60) were faced with 12 scenarios in which they either had to decide for themselves whether to apprehend a suspect or were informed about the corresponding decision by another police officer or a prosecutor. Participants then prepared questions for a suspect interrogation and evaluated the trustworthiness of the suspect's denial or confession. The same method was used in Experiment 2 but with law and psychology students (N = 60) as participants. In Experiment 3, psychology students (N = 60) prepared interrogation questions either by freely producing their own or by choosing questions from a preset list. Overall, apprehended suspects were interrogated in a more guilt presumptive way and rated as less trustworthy than non apprehended suspects. However, the tested debiasing techniques, primarily reducing cognitive load for the interrogating police officer, hold some potential in mitigating this bias. (PsycINFO Database Record