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Interview Technique Project (ITP)Factors affecting a verdict of guilty or not guilty

writer: YAMASAKI, Yuko (Ritsumeikan Global Innovation Research Organization, Senior Researcher) published: 2017-7

It is a great tragedy when a mistake is made in the determination of guilt in a criminal trial. Multiple factors affecting the determination of whether a person is guilty or not guilty have been examined in legal and psychological research. In this text we address three of these factors.

Interrogation techniques

Two examples of interrogation methods that have been put forward are the Reid technique and the PEACE model. In the former, the main aim is to obtain a confession, and the interrogator takes an explicitly adversarial posture toward the suspect with closed “Yes/no” questions such as “Did you do it?” (Buckley, 2013). In the latter, on the other hand, the aim is to collect information about the incident in question, and the interrogator is mindful of human rights and adopts a collaborative attitude. Interrogators mainly use open-ended questions that allow the suspect to respond freely, such as “Tell me everything that happened” (Naka, 2012a).
If you were a suspect, which form of interrogation would you want to receive?
If you were a lay judge, which form of interrogation would you more likely believe a confession from?

Because people have a tendency to try to obtain information that aligns with their expectations (Nickerson, 1998), interrogations using the Reid technique may make it difficult to discover facts that contradict expectations. Interrogations using open-ended questions, on the other hand, make it easier for suspects to contradict themselves if they are lying (Naka 2012b). Confession statements obtained using the PEACE model tend to be believed more than those obtained using the Reid technique (Yamasaki, Yamada, and Ibusuki, 2017).

Video recordings of confessions

In order to learn the truth, it is important to discard subjective notions about the object of inquiry and “look at it objectively.” But when this object is a person, it is difficult to get rid of our subjective opinions. For example, it is easy for people to have a negative impression of a person suspected of a crime, and the extent to which such an impression is formed differs depending on the method by which information is presented. Assessments of the voluntariness of a confession – whether the suspect confessed of their own free will – tend to be higher if the interrogation is presented as a video recording than if only audio is provided (Kassin, Meissner and Norwick, 2005). When the interrogation is shown on video, assessment of the voluntariness of the confession also differs depending on the camera angle used, and specifically on whether only the suspect is shown or the interrogator(s) are also in the frame.
If you were a suspect, which camera angle would you want to be used for the recording of your interrogation?
If you were a lay judge, which camera angle would you want to be used for the recording of an interrogation?

Lassiter and Andrey (1986) found that camera angles showing only the suspect increase the assessment of the voluntariness of the confession in comparison to camera angles showing both the suspect and the interrogator. Currently camera angles showing only the suspect are used in Japan, and a guilty verdict in which a video recording of a confession played a pivotal role was handed down in an April 2016 lay judge trial (Yoshizawa, 2016). In August of 2016, however, the Tokyo High Court found that “there is a risk of an inaccurate determination of reliability if the impression received from the manner of speaking during an interrogation is used to compensate for a lack of objective corroboration (regarding core elements)” and upheld the first trial in which video of the interrogation was not used as evidence (LEX25506536).


There are thought to be differences between individuals in their tendency to go along with the opinions of others.
If you were a lay judge, how much do you think you would be influenced by the determination of the majority?
In the film Twelve Angry Men, at first eleven of the twelve jurors are convinced that the defendant is guilty, but the lone dissenting juror points out contradictions in the prosecution’s evidence, and in the end all twelve agree on a verdict of not guilty. In most cases, however, there is a tendency for the opinion of the majority before deliberations begin to become the conclusion reached by the deliberating body (Davis, 1973). Kosaka et al. (2016) found that in deliberations to determine whether a suspect is guilty or not guilty, statements consistent with one conclusion are repeated, and inconsistent information is excluded. The fact that holding deliberations does not necessarily increase the validity of a determination of whether someone is guilty or not is very important.


  • Buckley, J. P.(2013). The Reid Technique of interviewing and interrogation. JOHN E. REID AND ASSOCIATES, INC. Retrieved from 31, 2017.)
  • Davis, J.H.(1973)Group discussion and social interaction: A theory of social decision schemes. Psychological Review, 80, 97-125.
  • Kassin, S. M., Meissner, C.A., & Norwick, R. J. (2005). “I'd know a false confession if I saw one”: A comparative study of college students and police investigators. Law and Human Behavior, 29, 211-227.
  • Kosaka, Y., Yamasaki, Y., Ishizaki, C., Nakata, T., Wakabayashi, K., & Sato, T.(2016). Proposal of Discussion Pattern in Japanese Citizen Judge System: Integration of Qualitative and Quantitative Analysis, Ritsumeikan Journal of Human Sciences, 34, 49-67.
  • Lassiter, G. D., & Audrey, A. I. (1986). Videotaped confessions: The impact of camera point of view on judgments of coercion, Journal of Applied Social Psychology, 16, 268-276.
  • Naka, M.(2012a). Improve investigative interviewing skills using scientific evidence : Development of forensic interviews and implications from the PEACE model, Japanese Journal of Law and Psychology, 12, 27-32.
  • Naka, M.(2012b). Scientification of suspect interviews: the PEACE as a model for information gathering approach. Japan Science and Technology Agency. Retrieved from 31, 2017.)
  • Nickerson, R. S. (1998). Confirmation bias: A ubiquitous phenomenon in many guises. Review of General Psychology, 2, 175–220.
  • Yamasaki, Y., Yamaada, N., & Ibusuki, M.(2017). Preliminary Research for Bias in the Fact Finding Process from the View of the Interrogation Techniques and Camera Angles, Ritsumeikan Journal of Human Sciences, 35, 67-79.
  • Yoshizawa, K.(2016). [scanner] Conviction for Tochigi Girl Murder Case. Interrogation Video Decisive, Yomiuri Shimbun Morning edition, 9 April, p.3.

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