One “Two” Many: An Examination of Solo Perpetrator Versus Team Perpetrator Serial Homicides

• Author: Julien Chopin,Enzo Yaksic,April Miin Miin Chai
• DOI: 10.1177/10887679211060030
• Published date: 01 May 2022
• Date: 01 May 2022
• Subject Matter: Articles

https://doi.org/10.1177/10887679211060030

Homicide Studies

2022, Vol. 26(2) 176 –198

© 2021 SAGE Publications

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DOI: 10.1177/10887679211060030

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Article

One “Two” Many:

An Examination of

Solo Perpetrator Versus

Team Perpetrator Serial

Homicides

April Miin Miin Chai1, Enzo Yaksic2,

and Julien Chopin3

Abstract

The current study examines the offender, victim, and crime characteristics between

solo perpetrators and team perpetrators of serial homicide. Cases on 1,137 solo

perpetrators and 254 team perpetrators were collected from the Consolidated Serial

Homicide Offender Database. Results showed team perpetrators were more likely

to be older than those who committed serial homicides alone. Offenders who never

confessed their crimes were less likely to participate in teams. In terms of victim

and crime characteristics, team perpetrators were more likely to target employees

or customers, have a lower victim count, and were more likely to exhibit sadistic

behaviors compared to solo perpetrators. Theoretical and practical implications from

this study are discussed.

Keywords

co-offending, multiple perpetrators, serial homicide, team homicide

Introduction

Although numerous studies on the characteristics of homicide offenders have been

conducted, the topic of multiple perpetrators has received less attention. According to

the U.S. Department of Justice’s (2011a) report, one in five homicides in 2008 involved

1Texas State University, San Marcos, USA

2Atypical Homicide Research Group, Boston, Massachusetts, USA

3Simon Fraser University, Burnaby, BC, Canada

Corresponding Author:

April Miin Miin Chai, School of Criminal Justice and Criminology, Texas State University, 601 University

Drive, San Marcos, TX 78666, USA.

Email: m_c1098@txstate.edu

1060030HSXXXX10.1177/10887679211060030Homicide StudiesChai et al.

research-article2021

Chai et al. 177

multiple offenders, representing approximately 20% of all homicides. This was an

increase from 11.3% in 1980. Younger offenders represented the largest age group

involved in multiple-perpetrator homicides (37.5% of 14–17 years old), followed by

young adults (27.5% of 18–24 years old), and adults (13.7% of above 25 years old).

Serious crimes such as homicides and stranger homicides present various challenges

to police investigators (Dauvergne & Li, 2006) which can be compounded by the

involvement of multiple perpetrators.

The majority of early multiple-perpetrator studies focused on juvenile offenses in

terms of co-offending behavior for non-violent crimes (e.g., Gold, 1970; Shaw &

McKay, 1931). Wolfgang (1958) published one of the first multiple-perpetrator studies

on serious and violent crimes which outlined the extensive descriptive information on

the offender, victim, and crime characteristics. Since then, several research studies on

homicide cases have suggested a delineation in characteristics between solo and multiple

perpetrators (e.g., Cheatwood & Block, 1990; Clark, 1995; Gunn et al., 2014; Juodis

et al., 2009; Park & Cho, 2019; Roscoe et al., 2012; Woster, 2020). In sexual homicide

studies, results showed that while there were some shared characteristics between solo

and multiple perpetrators, there were also apparent differences between the two types of

offenders, such as motivation (Higgs et al., 2019), victim characteristics, modus ope-

randi, and detection avoidance behaviors (Clarkson et al., 2020).

The consensus of past studies indicated that solo and multiple perpetrators of homi-

cide do differ in characteristics. Although informative, these studies were limited in

terms of small sample sizes ranging from 40 to 175 cases (e.g., Cheatwood, 1996; Clark,

1995; Juodis et al., 2009; Park & Cho, 2019). Further, these studies were mainly explor-

atory and were focused on single homicides, consequently neglecting serial homicide

events. Research has shown that homicide offenders with two or more victims were dif-

ferent from offenders who only killed one victim in terms of victim-offender relation-

ship, psychological disorder, and modus operandi (Fox & Levin, 1998; Harbort &

Mokros, 2001; Sturup, 2018). In an area where the subjects of interest are rare (e.g., less

than 1% of all homicides in the United States (US) were serial in 2010 (U.S. Department

of Justice, 2011b), scholarly studies of serial homicide offenders have generally been

idiographic or case study driven (Delisi & Scherer, 2006).

The low base rate of serial homicide events is further complicated by the variations

in its definition, data collection methods, and data sources (Yaksic, 2015). Thus, our

aim is to address the literature gap in both dimensions: (1) solo versus multiple perpe-

trators of homicide, and (2) serial homicide. The main focus of this study is to add to

and expand on the current knowledge by empirically investigating the differences

between solo and multiple perpetrators of serial homicide based on information col-

lected from the Consolidated Serial Homicide Offender Database (CSHOD).

Background

Multiple-Perpetrator Offending

Crimes committed by more than one perpetrator, or co-offending, have received nota-

ble attention in criminological research, particularly within juvenile and property