The decision-making process in Swedish forensic psychiatric investigations

Abstract

Expert opinions can have a substantial impact on how offenders with mental disorders are handled within the legal system. The decision-making process leading to these opinions needs to produce reliable and unbiased conclusions. The overarching aim of this thesis is to explore what characterizes the decisionmaking process of experts working with Swedish forensic psychiatric investigations. Study I uses data from interviews with experts. It shows that the decision-making process is flexible and organic, which creates a potential for efficiency and precision but may cause challenges with the reliability of the outcome. Study II explores the experts’ use of various information sources through three case vignettes. The results show that experts commonly use several sources in combination, but the characteristics of the case affect the number of sources deemed necessary. There is also noticeable variation among the experts regarding the medico-legal issues. Study III employs a multi-stage case vignette to emulate the process in actual investigations. It shows that experts formulate multiple hypotheses throughout the process and change these when presented with new information. The results also show variation among the experts’ opinions on medico-legal issues and that they are almost evenly divided at the end, when they feel the most certain in their opinions. Study IV combines interviews with experts with a 10-year cohort of cases referred by the court for additional review to identify characteristics of cases that make the medico-legal decisions difficult. Both experts and the court find ambiguous situations particularly difficult to decide on. While the experts emphasize clinical factors in this, the court is more affected by factors related to the crime in question and the overall judicial process. The court also appears to use information about the experts’ decision-making process to judge the reliability of the final expert opinion. In conclusion, there is a need to ensure that the decision-making process: a) mitigates difficult situations that may jeopardize the reliability and the validity of the final expert opinion, b) systematically uses variation between experts to strengthen the reliability of the final expert opinion, and c) provides the court with the necessary information to autonomously judge the reliability of the expert opinion.