To Know the Unknown: The Decline in Homicide Clearance Rates, 1980—2000

Against the backdrop of the precipitous decline in urban homicide clearance over the past several decades, this study examines factors that may be linked to within-city, over-time variation in homicide clearance rates from 1980 to 2000. Conceptual arguments focusing on case-level characteristics of homicides as well as the broader macrosocial context are delineated and empirically tested. Results from a fixed-effects regression analysis reveal that changes in clearance rates are linked to changes in the situational characteristics of murder incidents such as the percentage of cases involving strangers, firearms, other felonies, and arguments. In addition, within-city changes in immigration are found to be associated with lower clearance rates, whereas drug market arrests are associated with higher clearance rates. Contrary to politically popular assertions, clearance rates do not appear to be a function of changes in police personnel or workload.