Drawing upon data gathered during a 4-year ethnographic study of homicide investigation in Britain, we document the movement of 44 (suspected) homicide cases through the criminal justice process before drawing upon two case studies to unravel in detail how a homicide is determined and how suspects are identified, eliminated, or charged. We suggest that the progress of homicide cases through this process is best understood as the outcome of a set of socially organized scientific, legal, and occupational sensemaking practices, collaboratively deployed by institutionally authorized actors. We conclude that these practices are rendered visible only through detailed qualitative research.