Characteristics of Homicide Events and the Decline in Homicide Clearance

• Author: Yili Xu
• Published date: 01 December 2008
• Date: 01 December 2008
• DOI: http://doi.org/10.1177/0734016808320693
• Subject Matter: Articles

Characteristics of Homicide Events

and the Decline in Homicide

Clearance

A Longitudinal Approach to the Dynamic

Relationship, Chicago 1966-1995

Yili Xu

Platts Research and Analytics

Following the national pattern, homicide clearance rates in Chicago have continuously

declined for several decades. This study focuses on the influence of changing characteristics

of homicide events on the decline in homicide clearances. Most previous studies are not

suitable to address the decline issue because of their methodological limitations. The decline

is a longitudinal process and a cross-sectionally identified relationship could be a temporary

association at a particular point in time. The current study investigates all the key relationships

with two longitudinal methods: pooled cross-sectional time series and ARIMA and by con-

trolling for community-level factors. The results show that homicides involving concomitant

felony, Latino victims, strangers, and vehicle body location are significantly and consistently

related to the decline, whereas other previously identified predictors do not remain significant

over time. The current paper also explains how effects of homicide event variables can be

translated into actions and help improve clearance outcome.

Keywords: homicide clearance; decline in homicide clearance; characteristics of homicide

event; pooled cross-sectional time series; ARIMA

The homicide clearance rate has steadily declined in the United States from 91% in 1965

to 62% in 2005 (U.S. Department of Justice, FBI, 1965 & 2005). The trend of homi-

cide clearances in Chicago has followed a similar pattern: it declined from 94% in 1965 to

65% in 1995 (Block, Block, & the Illinois Criminal Justice Information Authority, 1998).

The declines have been a great concern for citizens, law enforcement agencies, and crimi-

nal justice scholars. It is important to understand what accounts for the decline for several

reasons. First, the clearance rate is related directly to one of the central underlying para-

digms of law enforcement—deterrence theory. The low clearance rates greatly undermine

whatever deterrent value derives from arrest, convictions, and incarcerations (Riedel and

453

Criminal Justice Review

Volume 33 Number 4

December 2008 453-479

© 2008 Georgia State University

Research Foundation, Inc.

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Author’s Note: I would like to thank the three anonymous reviewers whose comments and suggestions

are extremely helpful for enhancing the quality of the paper. I would also like to express my gratitude

to Dr. Virginia Fink for carefully reading the manuscript and offering detailed inputs on many aspects of

the paper. To contact the author, please send e-mail to: xuguolao@yahoo.com.

Jarvis, 1998; Wellford and Cronin, 1999). In addition, the decline can influence citizens’

sense of justice and personal safety and intensify fear of violent victimization. Finally,

because clearance rates are frequently regarded as a measure of police effectiveness, the

decline in the clearances signals an inability of the police to fight crime. As a result, it may

undermine the public’s confidence in the criminal justice system as well as police officers’

morale (Bucholz, 2002; Corwin, 1997; Riedel & Rinehart, 1996; Wellford and Cronin, 1999).

Several factors may have contributed to the decline in homicide clearances: (a) charac-

teristics of homicide events (Borg & Parker 2001; Litwin, 2004; Litwin & Xu, 2007;

Mouzos & Muller, 2001; Puckett & Lundman, 2003; Regoeczi, et al., 2000; Riedel, 2002;

Riedel & Jarvis, 1998; Riedel & Rinehart, 1996; Roberts, 2007; Wellford & Cronin, 1999);

(b) investigative procedures and practice by the police (Riedel & Rinehrt, 1996; Wellford &

Cronin, 1999); (c) the organizational characteristics of law enforcement agencies (Rinehart,

1994; Ridedel & Jarvis, 1998; Wellford & Cronin, 1999); and (d) the behavior of third par-

ties, characteristics of the community, and general social, political, and economic environ-

ments (Cardarelli & Cavanaugh, 1992; Davies, 2007; Ridedel & Jarvis, 1998; Riedel &

Rinehart, 1994; Wellford & Cronin, 1999; Xu, et al., 2005). So far, research on the decline

in homicide clearance has been sparse. Most studies in fact are geared to explain homicide

clearance but not its decline. Nevertheless, inquiries focusing on different dimensions of

explanations have all identified certain significant predictors of homicide clearances and

therefore contributed accumulatively to our understanding of the decline.

My latest review of the clearance literature shows a clear reality in which studies based

on characteristics of homicide events have dominated the landscape of the field. An undis-

putable fact is that this line of research has exerted a profound influence on the thinking,

reasoning, and decision making of law enforcement practitioners, scholars, and policy

makers. For example, it has become a popular belief that the decline in clearances is a result

of the decrease in the proportion of cases that are easier to clear, such as homicides that

occurred in homes, and the increase in cases that have a lower probability of being cleared

such as stranger homicide. This in turn influences the focus and strategy of police actions,

the advice law enforcement agencies give to the public, and policies that are proposed to

prevent and reduce violent victimization. As a result, further investigation on the roles

played by homicide characteristics in accounting for homicide clearance and its decline

maintains the continuity of an important research tradition on the subject.

Most previous studies in this category, nevertheless, are not really suitable to address the

issues of the decline because of their methodological limitations. Several recent studies

(Borg & Parker, 2001; Litwin, 2004; Litwin & Xu, 2007; Regoeczi, et al., 2000; Mouzos

& Muller, 2001; Puckett & Lundman, 2003; Roberts, 2007)have demonstrated some con-

nections between victim characteristics, situational factors, and homicide clearance.

However, they may not be able to answer questions about the actual decline in the clear-

ance because the decline is a longitudinal process and the methods used by most of the pre-

vious studies are essentially cross-sectional (see Appendix A). Given the changing social,

economic, and law enforcement environments in the past several decades, a reliable answer

to the question of the decline should be based on a longitudinal approach. The dynamic

nature of homicide clearances makes it likely that those significant relationships found in

cross-sectional studies are the results of some temporary associations that exist only at

particular points in time and may not have a persistent longitudinal presence.

454 Criminal Justice Review