Confessions during police interrogations: A Classification-Tree Approach
Most studies on confessions that occur during police interrogations have looked at the individual influence of various factors on the prevalence and probability of confession of suspects, neglecting potential interactions between these factors and their combined influence on the suspect’s decision on whether to confess to the crime. In order to bridge this gap, the present study proposes a profile-based approach using classification and regression trees as well as decision trees rather than the much more common variable-based approach to analyze interaction effects, hierarchical relationships, and the relative weight of a profile of factors in the decision-making process of the suspect. The study is based on self-reported data for a sample of 211 inmates in a Canadian penitentiary. Different profiles and combinations of factors were found to play more or less important roles in the decision-making process and the likelihood of a confession. In particular, the results highlight the importance of situational factors and the key role of the police and investigators in the suspect’s decision to confess or not during police interrogation. The decisional profiles observed and the importance of explanatory factors are discussed in light of current knowledge about confessions and the practical implication of these results for police interrogations are noted.