Chapter 1 gives students with little or no legal background a primer on how the law works. The chapter provides a brief historical background of how law is created and its sources, how to read and find case law, and the role of precedent in rules-based and analogy-based reasoning (pp. 10–11). The geography of legal cases is provided to introduce students to common legal terms and how they operate in criminal cases: due process, objectively reasonable, reasonable man, totality of the circumstances, good faith, harmless error, and the quantum of evidence required for official action from investigation to conviction (pp. 12–15). Criminal theories about why offenders commit crime and the purposes of punishment are illustrated through the case excerpt of U.S. v. Brewer (2013), with a discussion of the role of criminal justice actors. The basis of civil liability and corresponding limited immunity are illustrated in the case excerpt of D.C. v. Wesby (2018) (pp. 24–26). Making the Courtroom Connection explores the federalism tension in withholding federal grant money for the so-called “sanctuary cities” that refuse to assist federal immigration law enforcement efforts (p. 29). The chapter ends with a description of federal and state sovereignty examined in the case excerpt of Murphy v. NCAA (2018) and federal jurisdiction via the Constitution’s Commerce Clause illustrated by the case excerpt of Gonzales v. Raich (2005) (pp. 28–32).