This thesis seeks to account for and understand the reasons for the rapid diffusion of Closed Circuit Television (CCTV) surveillance systems in public places across the UK. This is achieved by examining the policy processes and governance structures associated with the diffusion of CCTV systems in local authority settings. An underlying theme in the thesis is that because CCTV is a uniquely powerful technology, its introduction and subsequent diffusion, must be understood in its political and policy environment. To address this concern the thesis develops a framework of understanding based on different perspectives of the policy process, where each perspective is based on the evolution of a core idea or concept. Each of the dominant perspectives identified, offer a different way of `seeing' or comprehending the policy process, and consequently, a different way of explaining the diffusion of CCTV. This is significant as it shows that CCTV must be understood as a policy and a technological phenomenon, and that the processes that explain policy development and technological diffusion are closely intertwined. A key objective of the thesis has been to design a scientific methodology in which to embed the development of the theoretical framework and the empirical research process. In doing so the thesis developed a coherent and comprehensive way of understanding contemporary information age policy processes and the diffusion of CCTV. The main empirical elements of the research were a national survey of local authorities and three detailed local authority case studies. These established that local authorities had installed CCTV into a wide range of public places and that diffusion had involved a variety of strategic, deliberative, consultative and evaluative processes. For local authorities, CCTV represents both a radical shift in policy and a highly institutionalised response to perceived problems in society.