Sala Grande - 19th IAFS World Meeting - 9th WPMO Triennial Meeting

5
Author(s): Tkatchouk M 1 ; Rebocho MF 2
19 th IAFS WORLD MEETING
9 th WPMO TRIENNIAL MEETING
5 th MAFS MEETING
OFFENCE BEHAVIOURS AS PREDICTORS OF OFFENDER CHARACTERISTICS IN SEX OFFENDERS
Institution(s): 1 SIMON FRASER UNIVERSITY; 2 UNIVERSIDADE FERNANDO PESSOA
Abstract: Criminal Profiling (CP) is an investigative tool used to assist with suspect prioritization in criminal investigations by providing a
profile of offender characteristics that can be used to select a number of viable suspects from a large potential suspect pool. CP is used
despite lacking empirical support. Profilers claim to predict the background characteristics of an offender, based solely on his or her
behaviour during the commission of one or more crimes. Thus, logically, a necessary condition of CP is the existence of relationships
between offence behaviours and offender characteristics. We argue that it needs to be established through attempts to identify groups
of offenders that are different with respect to offence behaviours and offender characteristics. In the current study, an attempt was
made to derive a taxonomy that classified the population of male Portuguese incarcerated sex offenders into groups that are different
with respect to offence behaviours and offender characteristics. The participants in this study were 216 male Portuguese incarcerated
offenders, convicted for sexual offenses involving direct physical contact with their victims. Data were gathered using an instrument
built to collect information from the participants’ institutional records and guide in-depth, semi-structured interviews with offenders. In
case of any discrepancies between the offender’s account and the institutional records, information from the institutional records was
used. The variables that were coded were divided into two sets, the first set consisting of 156 offence behaviour variables (the kind of
information that would be available for profile generation), such as: victim selection (child versus adult), approach strategy, weapon
use, and levels of coercion and injury inflicted on the victim, and the second, 45 offender characteristics variables (the kind of
information that should be contained in a profile), such as: age, employment status, criminal record and psychiatric/psychological
problems. Initially, a Categorical Principal Component Analysis (CATPCA) was applied to the 156 offence behaviour variables to reduce
their dimensionality to the number of dimensions that accounted for 90% of the variability in the data. The resulting principal
component variables were retained for input into a Hierarchical Cluster Analysis (HCA). The type of HCA used was Ward’s method; the
optimal number of clusters was selected by inspecting the dendrogram. Finally, each cluster was described in terms of the offence
behaviour and offender characteristics variables. Thus, in this study, a sex offender taxonomy that supports the necessary condition of
CP identified, namely the existence of relationships between offence behaviours and offender characteristics, has been derived.
Although this finding is preliminary, it suggests that the necessary condition of CP identified is in place in Portugal and paves the way for
replications of this finding and further CP research.
Keywords: Sex Offenders; Criminal Profiling; Offence Behaviours; Offender Characteristics; Offender Taxonomy