In this chapter, the authors, all of whom are both researchers and clinicians—experienced in forensic or clinical psychology or psychiatry—draw on the scientific literature and their different clinical perspectives to reflect on what can be considered “best practices” in the rehabilitation of perpetrators of sexual homicide. Recommendations are made for assessment, treatment, and management from custodial settings to the community. To do this, factors that are central to a comprehensive forensic case formulation are considered, from the role of anger, violence, and sadistic fantasy to psychopathology and differentiating characteristics compared to non-homicide sexual offenders or as a function of victim type (male, female, child). The chapter also addresses an often overlooked fact that most perpetrators of sexual homicide do not kill more than once. Scientific knowledge pertaining to serial sexual homicide offenders is therefore looked at with the aim of understanding this phenomenon and to consider where limitations remain in the evidence base underlying assessment and management practices when working with both serial and non-serial offenders.