An Analysis of Mobility Patterns in Sexual Homicide

• Date: 01 May 2020
• Published date: 01 May 2020
• DOI: 10.1177/1088767919884601
• Author: Stefano Caneppele,Julien Chopin,Eric Beauregard
• Subject Matter: Articles

https://doi.org/10.1177/1088767919884601

Homicide Studies

2020, Vol. 24(2) 178 –202

© 2019 SAGE Publications

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DOI: 10.1177/1088767919884601

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Article

An Analysis of Mobility

Patterns in Sexual

Homicide

Julien Chopin1, Stefano Caneppele2,

and Eric Beauregard1

Abstract

This article—based on a national data set (N = 173)—focuses on extrafamilial sexual

homicides and their spatial mobility. The study combines the location of the crime

scene and the offenders and victims’ residences in mobility crime triangles. The findings

reveal that most of the homicides fall within the categories of offender mobility and

total mobility. Our results show the validity of the distance decay function, with over

70% of homicides occurring within 10 km of the offender’s residence. It appears

that under certain circumstances, sexual murderers perceive their surroundings as a

safe place to commit a homicide. Finally, the study proposes a four-category spatial

typology of sexual homicide.

Keywords

crime scene, policing, investigation, profiling, stranger, victim/offender relationship,

victimization

Introduction

The distance traveled to commit a crime is important not only for theory but also

for the investigation of these crimes. Although there has been considerable research

on the journey-to-crime, very few studies have focused on sexual crimes. However,

the studies that have examined sexual crimes have found that similar to other per-

sonal crimes—such as homicide—sex offenders tended to commit their crimes

close to home (see, for example, Alston, 1994; Andresen, Frank, & Felson, 2014;

1Simon Fraser University, Burnaby, British Columbia, Canada

2University of Lausanne, Switzerland

Corresponding Author:

Julien Chopin, School of Criminology, Simon Fraser University, 8888 University Drive, Burnaby, British

Columbia V5A 1S6, Canada.

Email: julienc@sfu.ca

884601HSXXXX10.1177/1088767919884601Homicide StudiesChopin et al.

research-article2019

Chopin et al. 179

Beauregard, Proulx, & Rossmo, 2005; Block, Galary, & Brice, 2007; Chopin &

Caneppele, 2018, 2019; Davies & Dale, 1995; LeBeau, 1987a, 1987b, 1987c,

1992). Recently, studies have examined the traveling patterns of sexual homicide

offenders (see Beauregard & Martineau, 2017; Martineau & Beauregard, 2016).

Maybe because sexual homicide is considered a hybrid crime—combining homi-

cide and sexual assault—results were different. For instance, studies have found

that sexual murderers may travel further from their residence to the initial contact

scene or choose body disposal sites further from home (e.g., Martineau &

Beauregard, 2016), suggesting that at least some sexual murderers are willing to

travel longer distance when committing their crime. Although interesting, these

findings were limited by the measure used for the distance traveled.

Therefore, the aim of this study is to explore three questions related to the dis-

tanced traveled by sexual murderers. First, the study will describe the mobility of

extrafamilial sexual homicide (ESH) by analyzing distances between the offenders’

residences, victims’ residences, and the crime locations. Also, our goal is to classify

ESH cases in two pre-existing crime mobility triangle typologies and analyze their

heuristic value for ESH. Finally, this research aims to explore the relationship

between criminal mobility and individual as well as modus operandi characteristics.

In this study, the focus was put on the description of ESH mobility using the triangle

mobility methodology as well as the factors associated with it (instead of some of

the concepts associated with environmental criminology, such as distance decay,

buffer zone, and anchor points).

Literature Review

In criminology, the concept of criminal mobility usually refers to the distance traveled

by offenders from their home to the crime location (i.e., the journey to crime). One

recurrent finding arising from the journey to crime literature is that offenders travel

relatively short distances when committing their crime. However, Beauregard and

Busina (2013) suggested that the use of the journey to crime as the sole measure of

criminal mobility comes with several assumptions that are not always met, such as (a)

assuming that the home location of the offender is the starting point of the crime trip

(i.e., a crime trip may originate from a different location, such as the offender’s work-

place; see Bernasco, 2010); (b) assuming that the entire criminal event takes place at

the same location, even in cases of crimes involving a mobile human victim

(Beauregard, Rebocho, & Rossmo, 2010); and (b) assuming that the concept of mobil-

ity can and should only be measured in terms of distance traveled, neglecting the other

dimensions of the mobility concept (see Rossmo, Lu, & Fang, 2011).

Due in part to the various limitations reviewed above, complementary approaches

to the measure of criminal mobility were suggested. Leclerc, Wortley, and Smallbone

(2010) conceptualized geographic mobility as the use of multiple locations for the

purpose of repetitive sexual contact with the same victim. In other words, they exam-

ined whether offending differences existed between child molesters who used multiple

locations for sexual contact and those who used a single location for the entire