Balancing the scales of justice: The communication of scientific evidence and the impact on case progression and prosecutorial decision-making in Scotland since 2009

The criminal justice system can often be likened to a machine with intricate interactions between constituent cogs. Some such cogs in the machine are scientific evidence, its communication, and how it affects the decision-making process in respect of case progression. Though there is a wider machine of criminal justice, there are sometime disparities in how different types of cases progress through the criminal justice system. Sexual and non-sexual violent crimes can be some of the most difficult to progress through the criminal justice system. Since 2009, there have been several legislative changes aimed at tackling case attrition. The overarching aim of this thesis was to understand the role of the communication of scientific evidence and to what extent it impacts case progression and prosecution decision-making in serious sexual and non-sexual violent crime in Scotland since 2009 This thesis examines the issues of case progression, investigation, and prosecution through a novel approach by conducting research in three data collection phases and objectives. The first being to examine the communication of scientific evidence and decision-making involved during the investigation and prosecution of rape cases in Scotland from an organisation that is independent of the criminal justice process, Rape Crisis Scotland, to gain insight into the handling of rape cases in Scotland from an alternative viewpoint. Findings suggest real discrepancies in how national criminal justice agencies operate showing that although there may be a national framework, this is not always the reality in different regions of Scotland. The second objective was to determine to what extent, if any, variations in methods of communication of uncertainty affects decision-making in criminal justice case progression – specifically the decision to prosecute a case and the confidence in that decision. Data collected in this citizen science project which shows there are small intricacies in how different groups decide whether to prosecute cases and the confidence in which they make those decisions. The final objective was to determine to what extent potential jurors attribute trust and weight to different evidence types when presented with them in a criminal case. The potential juror pool in Scotland being largely made up of non-scientifically trained lay people. This final phase showed that there are subtle differences in how different groups attribute trust and weight as potential jurors in different criminal cases based on their engagement with popular culture representations of crime and criminal justice. These phases combine to illustrate the processes involved in sexual and non-sexual violent crime case progression in Scotland since 2009 in a new way to show that many of the criminal justice reforms in Scotland have had little or no impact on case progression. Moreover, there is limited evidence to suggest that there are subtle differences between how those who have previously served as a juror compared with those that have not, interact with different types of evidence in different type of crimes as well as their decisions and decision confidence in prosecutions. Key recommendations for policy and future research are made and discussed.