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

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

A true denial or a false confession? Assessing veracity of suspects' statements using MASAM and SVA.

Previous research on statement analysis has mainly concerned accounts by witnesses and plaintiffs. In our studies we examined true and false statements as told by offenders. It was hypothesized that SVA and MASAM techniques would enhance the ability to discriminate between true and false offenders' statements. Truthful and deceptive statements (confessions and denials) were collected from Swedish and Polish criminal case files. In Experiment 1, Swedish law students (N = 39) were asked to assess the veracity of statements either after training in and usage of MASAM or without any training and using their own judgements. In Experiment 2, Polish psychology students (N = 34) assessed veracity after training in and usage of either MASAM or SVA or without prior training using their own judgements. The veracity assessments of participants who used MASAM and SVA were significantly more correct than the assessments of participants that used their own judgements. Results show, that trained coders are much better at distinguishing between truths and lies than lay evaluators. There were significant difference between total scores of truthful and false statements for both total SVA and MASAM and it can be concluded that both veracity assessment techniques are useful in assessing veracity. It was also found, that the content criteria most strongly associated with correct assessments were: logical structure, contextual embedding, self-depreciation, volume of statement, contextual setting and descriptions of relations. The results are discussed in relation to statement analysis of offenders' accounts.