A small body of literature has recently developed which examines the availability and collection of physical evidence from crime scenes and forensic laboratories' performance and output. The monograph discusses these works as well as those addressing the significance of physcial evidence in investigations. An overview of primary studies in police productivity is also important since any effort to incorporate measures of forensic effectiveness into a police operation must be integrated with overall agency goals and evaluation procedures. The monograph also discusses the general cost-benefit literature. About 50 references are cited.