An expanding body of criminological literature recognizes the diverse nature of events culminating in what is commonly known as homicide. Creating effective programs to prevent homicide requires an understanding of the various underlying homicide syndromes; this understanding requires information that is sufficient to categorize the events completely and accurately. However, the Uniform Crime Reports and the Mortality System of the National Center for Health Statistics were not designed to support detailed studies of the causes and correlates of homicide. Homicide researchers who want to use these data are often hampered by problems associated with missing data and a lack of explanatory variables. The Bureau of Justice Statistics of the United States Justice Department is creating a comprehensive database that includes information on homicide victims, information derived from police investigations, and information for a sample of cases as they progress through the criminal justice system. This project is called "The Study of Homicide Caseflow." When completed, this study will aid studies of aspects of homicide that currently cannot be addressed using existing data. Data for Chicago provide an example of the effect of additional information on the matching of homicide cases. Tables, charts, and 22 references