Drawing upon data gathered during a four-year ethnographic study of homicide investigation in Britain, we explore how criminal justice actors use science and technology during homicide investigations and with what effect. Specifically, we present preliminary findings from an in-depth analysis of 44 homicide investigations across four British police forces and illustrate how detectives, forensic scientists and other experts (including barristers) make-sense of information, intelligence and evidence collectively at different stages of the investigative process. We consider some of the opportunities and challenges faced by detectives, scientists and other experts when performing sense-making work within homicide investigations.