This talk provides an overview of the primary data sources for death penalty research and a glimpse at some of the limitations of working with these sources. Examining each stage of a capital prosecution—from the police investigation of a potentially capital murder to a governor’s decision to grant clemency sparing the life of a death-row inmate—is necessary to understand the process as a whole. But arbitrary factors like local politics, luck, and institutional legacies limit researchers’ ability to collect data about each decision point, making researchers’ attempts to follow cases across multiple stages exceptionally difficult.