The term “police” derives from _polis_, a Greek word meaning “city-­state.” In its original meaning, “police” refers to the state’s responsibility to protect public welfare. “Police” does not officially appear in the English language until the mid-­eighteenth century, when it is adapted from French, and it is not used colloquially to refer to the civil institution tasked with enforcing laws and detecting crime (“the police”) until the nineteenth century. The word “police” does not appear in the U.S. Constitution, but the concept was discussed in contemporary writings on the function of government. In these writings, it was argued that the state’s police powers were analogous to the individual’s natural right to self-­defense. When individuals were attacked, they had the right to defend themselves, and when society was attacked, it had the same right to self-­defense by whatever means. Police powers were necessary to preserve the peace of society. Without them, there was no way for society to defend itself against imminent threats to public health and safety (Dubber 2005). In federal and state courts, these discretionary powers were justified by imagining threat scenarios that required immediate preventive action. In some cases, these threats were objects, whether rickety buildings or ticking...