This research builds on earlier studies conducted by the Department of Justice (DOJ) that focused on the federal death penalty system. It responds directly to a call for research into the process by which homicide cases are investigated and how and why some of those cases enter the federal system and others enter the state system. The findings make clear that no one factor likely predicts whether homicide cases are brought to the federal system. Instead, the findings suggest a framework that organizes the myriad factors that influence decision-making into two categories: openness that is influenced by expertise, capabilities, and track record; and coordination and interaction that is influenced by task forces and other mutually beneficial relationships reinforced by shared crime concerns and respect. Using qualitative research techniques, this study examined the processes by which criminal cases, especially homicide cases, entered the federal criminal justice system. The research plan called for ten districts, which were selected purposefully and should not be considered representative of the 94 federal districts. Researchers visited nine federal districts and interviewed federal, state, and local investigators, prosecutors, and defense attorneys who potentially played a role in determining whether homicide cases were investigated and prosecuted in the state or federal systems. The findings in this report are limited to the first four districts analyzed. These districts are geographically diverse, with and without state capital provisions, and sent among the highest and lowest number of cases to DOJ for capital consideration during the study reference period, 1995-2000.