There has been a surge of recent interest by social work researchers in conducting research in criminal and juvenile justice settings. This is largely fueled by the tremendous increase in incarceration over the last several decades, with millions more in probation or parole at any given time. Rising expenditures strain state and local budgets and many individuals are spending much of their adolescence and young adulthood in correctional facilities. Despite the profound impact that the criminal justice system has on client populations served by social workers and related professions, there are few practical resources available to guide research in these settings. This Pocket Guide fills a critical gap in the literature by providing state-of-the-art techniques for researchers, graduate students, and agency administrators. Research in criminal justice settings represents unique challenges that require rigorous designs and a suite of methods, as well as the tools to navigate a complex system. With this accessible and practical guide, readers will encounter a wide range of study types and data sources, along with strengths and weaknesses to consider with each as they conceptualize, implement, and analyze their research. Crucially, the authors also provide advice on how to gain and manage access to these settings, as well as templates for preparing a successful Institutional Review Board application. Step-by-step procedures elucidate the use of extant and administrative data, and practical case examples, sample forms, and measures will help researchers implement their studies quickly and effectively.