Analysis of Variables Affecting the Clearance of Homicides: A Multisite Study

• NCJ Number: 181356
• Author(s): Charles Wellford; James Cronin
• Date Published: 1999
• Length: 175 pages
• Publication Series: NIJ Research Report
• Grant Number(s): 96-IJ-CX-0047
• Agencies: NIJ-Sponsored
• Publication Type: Report (Study/Research)

Annotation

This study was designed to develop a better understanding of the variables that are associated with the clearance of homicide cases.

Abstract

Using data provided by the FBI, the study constructed a data set for 170 cities that consisted of their levels of total crime and homicide; the demographic characteristics of the city; and the number of homicides and other crimes cleared by an arrest for 1980, 1985, 1990, 1991, 1992, 1993, and 1994. In addition to creating and conducting preliminary analyses of these data, the researchers focused on 20 of the largest cities to determine any variations in their clearance rates, changes in clearance rates through this period, and levels of homicide. The analyses showed that clearance rates for most of these cities were relatively stable from 1980 through 1994, although the cities varied considerably in their rates of clearance of homicide. Four cities with relatively stable patterns of clearance and high levels of homicide were selected for detailed analysis of homicide clearance rate variables. The three instruments used in the study yielded data on the circumstances surrounding the homicide case, the investigation process, and the organizational structure of the police departments. The study found that the activities of the first responding officers to secure the scene, to identify potential witnesses, to preserve evidence, and to initiate and participate in neighborhood surveys is critical to homicide clearance rates. The speed with which homicide detectives, evidence technicians, and medical examiners are notified and the time it takes them to respond to the scene are associated with clearance. The assignment of three or four detectives is optimal for clearing a case. Policies that allowed responding detectives to stay on the case as long as they thought necessary without seeking approval were critical. The data also suggested the increased importance of computer checks of various types, particularly checks on guns, suspects, and victims. 12 references and appended study instruments and data