This report is intended as a guide for achieving effective homicide investigations, based on policies, practices, and strategies that police departments have found effective. The chapters address homicide unit policies and procedures; the detective and supervisor selection process; investigations training; staffing and caseload management; supervision, accountability, and oversight; cold case unit; internal coordination; external coordination; homicide unit equipment and technology; and digital evidence, crime analysis, and beyond. One of the major themes is that strong policies, training, and organization are critical to effective homicide investigations. A second emphasis is the level of resources. If there are too few detectives responsible for too many cases or detectives lack training on advances in forensics and other critical investigative techniques, then clearance rates will suffer. A third important finding from this study is that the nature of homicide investigations is constantly changing. Homicide investigations are increasingly relying on the analysis of digital evidence produced by smart phones, computers, social media accounts, and video footage from security cameras and police body-worn cameras. In addition, advances in crime analysis have improved the identification of crime patterns and links between people involved in crimes. This guide recommends types of training, tools, and technologies police agencies need to identify and collect digital evidence and upgrade crime analysis. Four appendixes provide supplementary information and a list of resources.