This book reveals what happens to applications for post-conviction review when those in England and Wales who consider themselves to have been wrongfully convicted, and have exhausted direct appeal processes, apply to have their case assessed by the Criminal Cases Review Commission. It presents the findings of the first thorough empirical study of decision-making and the use of discretion within the Commission. It shows how the Commission exercises its discretionary powers in identifying and investigating possible wrongful convictions for rehearing by the Court of Appeal. The research it draws on - a three year empirical study - comprises a mixed-method approach of quantitative and qualitative analysis of case files and aggregate data, as well as interviews with decision makers and observations of committee meetings to fully grasp the workings of the organization from a socio-legal perspective and to understand how discretion operates at the individual and institutional level. The study starts from the premise that the legal framework within which the Commission works - the probability of a case being likely to succeed at the Court - is neither rigid nor uncomplicated. While it is a legal test, and is therefore applied according to statute and case law, it could also be seen as a fluid concept that must be determined on a case-by-case basis, drawing in various cultural and structural variables as well as the more obvious features of the case and prior decisions of the Court. The book not only explores how decisions about which cases are likely to satisfy this test can be shaped by factors beyond the law, but examines how the Commissions' investigatory process is influenced by non-legal factors. As the review process is potentially open-ended there is considerable scope for discretion, for thorough examination of all possible avenues, or for choosing a more superficial consideration of the case. The different professional backgrounds of Commission staff may influence investigations and decision-making, as could a range of other cultural and structural variables that may come into play over the months or years of scrutiny, enquiry, discussion, and meetings that take place during the investigation of each case. The Commission will be influenced by internal guidelines, but may also be persuaded by campaigners and the media and even by the personality of decision-makers or the supervision they receive. In consequence, there may be some variability across cases, and over time. This book will demonstrate this variability and consider, from a normative perspective, how difference in approach across similar cases can be defended.