We begin our discussion of the major institutions of criminal justice by considering its “executive,” law enforcement, or policing dimension. Classic liberal democratic theory saw the policing role simply as one of ensuring that those who violated rights were called to answer for what they had done. But contemporary policing is much less clearly defined. Here we review the scope of the police role and the limits of police discretion in fulfilling that role, and then consider two of the important strategic powers that enable police to fulfill their role: coercion and deception. For obvious reasons these present great moral challenges.