The authors construct a measure of the seriousness of a crime, particularly homicide, from a tetrachoric correlation matrix and estimate the effects of this variable on a prosecutor's decision to seek death penalty for an accused killer. This study shows seriousness to be a unidimensional latent variable that includes both legal and extra-legal factors such as race of the offender and race of the victim. The seriousness variable accounts for approximately 40 percent of the variation in Kentucky prosecutor's decisions to seek the death penalty. These results suggest that prosecutors are influenced not only by legal aspects of a homicide case, but also by extra-legal, social factors. In this measurement model, racial effects seem to influence the capital sentencing process in Kentucky. 5 tables and 32 references