This chapter sets out a methodology for assessing the harms of crime systematically and empirically—namely, the harm assessment framework—which supports the analyses in subsequent chapters. It discusses the origins of the approach in literatures that span disciplines and presents the components of the framework, consisting of a set of analytical tools (data template, taxonomy, severity and incidence scales, and priority matrix) and a multistep process for applying them. The harm assessment framework weaves the tools together to identify, evaluate, and rank harms from damages to functional, material, and other interests, which are borne by individuals, private-sector entities, government, and the social and physical environment. In a final step, it also investigates causality, including the role of policy and related law-enforcement practices in shaping harms. All told, the framework addresses many of the conceptual and technical challenges of harm assessment raised previously.