In this chapter, the authors discuss the functional competencies required to conduct psychological evaluations of police candidates and officers, including “occupational competence,” which includes knowledge about the essential functions of police officers, their working conditions and chain of command, and the psychological demands and stressors of police work. The authors provide guidance on how to self-assess for competency, as well as for bias, that, in relation to a particular referral, may preclude a competent assessment. Included are an explanation of how contemporary challenges in policing may shape the criterion standard for assessing psychological suitability and fitness and a brief summary of six interdisciplinary professional practice standards and guidelines documents—from the United States and Canada—that are especially pertinent to evaluations of police suitability and fitness.