This research project takes advantage of the unique opportunity to study the natural history of the onset and desistance of the "epidemic" of drug-related homicides in New York City. We also examine the extent to which criminal justice policy influenced the course of the homicide epidemic.

In New York City, drug-related violence contributed to sharp increase in homicides beginning in 1985, peaking at a record rate in 1991. Estimates from police and injury surveillance systems suggest that over half the homicides in these years were drug related, often associated with drug market transactions. These record homicide rates led to intensive street-level law enforcement efforts beginning in 1987, resulting in unprecedented rates of drug arrests and sharp increases in the state prison population.

In 1992, homicide rates in New York City began a record decline that has continued. Although ethnographic studies suggest that drug markets have contracted since 1992, we do not know the extent to which the homicide decline includes decreases in drug-related homicides.

This project integrates data from criminal justice and public health data bases to assess the effects of criminal justice policy on the rise and decline in homicides generally, and drug-related homicides specifically. First, we will identify the locations of each homicide event and develop spatial analyses to assess changes within specific neighborhoods closely tied to drug markets. Second, we will develop estimates of drug and other law enforcement activity at the local level using police department data on drug and other types of arrests by precinct. Third, we will compute population and other social structural parameters estimates to test competing explanations for the decline in homicide rates. We will test the effects of law enforcement and demographic change on within-neighborhood drug-related and total homicide rates over time, and will examine cross-level effects of precinct-level enforcement patterns with local socioeconomic data as they influence neighborhood-specific homicide rates. Finally, we will chart the migration of drug-related homicide events across neighborhoods over time, and link these spatial changes to shifting patterns of enforcement.