This chapter discusses how a criminal justice system can operate without state input. Conventional wisdom states that the state is an essential aspect of any criminal justice system, based on three assumptions: first, only the state can delineate exactly what acts constitute a crime; second, the purpose of the criminal law is a collective, society-wide statement of condemnation against certain acts; and third, coercion and violence are often used in a criminal justice system and the state has a monopoly on the leigitmate use of force. The chapter rebuts each of these assumptions. First, the chapter notes that, through a combination of natural law and societal mores, there is a consensus on what actions should be considered criminal, even without a state legislature promulgating specific crimes. Second, private responses to criminal activity can further society's goals of deterrence and retribution, even though they also fulfill the needs of the private actors. Third, many responses to criminal activity do not require coercion or force and, even if they do, the state has authorized private uses of force in certain circumstances.

This chapter traces the history of each phase of private law enforcement, from private policing, to private adjudications, to private dispositions (also known as vigilante actions).The chapter points out that, throughout history, private parties have played a larger role in the criminal justice system than most people expected.