This book addresses the fundamental questions related to what is meant by "crime," and it suggests why a classification is an important framework. It then summarizes the current primary sources of nationally compiled crime statistics, including an illustrative sample of data collection that is not currently considered part of the Nation's crime statistics infrastructure, but which may provide useful "crime" or contextual information. In addition, a chapter reviews extant and historical classifications of crime, including those used in other countries. The classification developed by the panel is a conceptual framework, relative to which crime statistics will eventually be collected. The panel anticipates that the classification will be used as a blueprint for designing data collection. The classification attempts "to partition the entire space of 'crime' so that a particular offense behavior corresponds to one and only one category." This work reflects panel discussions from two workshop-style panel meetings held in the summer of 2014. The second and final report will be a detailed discussion of methodological and implementation plans.