Chapter 1: Introduction: Chapter 2: Literature Review We will conduct a state-of-the art review of the available evidence on BWV by focusing our efforts on several lines of research: estimating the effect of BWVs on assaults and injuries; guidelines on use (with a focus on mandatory versus non-mandatory policies); activation trends; and the use of metadata to explore the issue of 'use' of BWVs; the perceptions of frontline members of staff; and the distal effects of BWVs (i.e., the effect of BWVs evidence in the criminal justice system. Chapter 3: The missing gaps in the literature Based on the literature review, we will identify what is missing from the literature at this stage. We will pay particular attention to the missing gaps for non-police BWVs and what can be done to fill these lacunae. We will focus on the settings in which we try to answer these questions: the train operating company environment, which is heavily involved in assaults, injuries, and problems vis-à-vis a population of millions of passengers every year. The setting of the project will also be highlighted here. Chapter 4: Estimating the effect of BWVs on assaults and injuries What is the overall effect of equipping public-facing TOC employees with BWVs in terms of assaults, injuries, and serious injuries relative to periods when BWVs were not deployed? Within that, we are specifically interested in the effect of mandated versus voluntary use of BWV policies, as some TOCs use one or the other policies.

Chapter 5: Activation Trends What are the trends of body-worn activation across end users, and can we identify a power-few law with a non-normal distribution of use amongst TOCs, train stations, or employees? We turn to metadata - the information that is stored on the BWVs and can then be used to analyse trends in the useability of BWVs in field operations. Chapters 6-7: What are the perceptions of frontline members of staff? We attempt to address the perceptions of end users. What are the views of employees on BWVs, and are they overall receptive to these devices? In this sense, we can also ask whether support for BWVs can be predicted based on a series of key dimensions raised in the literature--technological considerations, relationships with members of the public, perceived utility of BWVs, etc.--as antecedents of BWV usage. We will provide evidence from a nationwide survey in the TOC environment as well as focus group findings. Chapter 8: Distal effects of BWVs How do prosecutors perceive the utility of BWVs in criminal justice proceedings and prosecutorial decisions? Based on a questionnaire comprised of all police prosecutors who bring cases to court on behalf of the train operating companies, we provide informative information on the utility of BWVs in these decision-making processes. Chapter 9: overall discussion and policy recommendations Based on the evidence and in relation to the available evidence, what have we learned about the utility of BWV? We will provide concrete guidance for policymakers and suggestions for future research in this field. Appendices We provide for the general readership copies of our instruments and data from the focus groups for future scholars to conduct further analyses.