Treatment of Sex Offenders

292
P. Lussier
Offending Trajectories and Desistance from Crime
In order to account for the heterogeneity of longitudinal pattern of development and
the dynamic aspect of offending over time, researchers theorized that desistance
patterns are an integral part of offending trajectories (e.g., Le Blanc & Fréchette,
1989 ; Moffitt, 1993 ). Offending trajectories consist of patterns delineating onset,
course, and termination of offending over time. This perspective asserts that there
are relatively few but rather specific and predictable longitudinal patterns of offending.
From a trajectory perspective, desistance from crime is hypothesized to be
intrinsically linked to both the age of onset of offending and the course of offending.
There is a consensus that age of onset of offending is statistically related to longer
criminal careers (e.g., Blumstein et al., 1986 ; Farrington, 2003 ; Loeber & Le Blanc,
1990 ). Hence, researchers have formulated hypotheses regarding desistance from
crime based on the age of onset of offending distinguishing early and late starters,
with an emphasis on the adolescence–adulthood transition (e.g., Moffitt, 1993 ).
Researchers generally recognize the presence of an early-onset, persistent patterns
of general delinquency (also known as life-course persisters) who tend to escalate to
the most serious forms of crime and delinquency, such as violent and sexual offenses
(Moffitt, 1993 ; Le Blanc & Fréchette, 1989 ). Researchers have theorized that lateonset,
also known as adolescence-onset offending, is more likely to be associated
with a pattern of desistance prior to or immediately during the initial adult transition
period than early, childhood-onset of offending. The explanation rests on developmental
perspective assertions that late entry into delinquency more typically
involves youth who have benefited from prosocial influences and learned the necessary
prosocial skills to adjust to the adolescence–adulthood transition prior their
delinquency involvement (e.g., Moffitt, 1993 ). To measure and identify such patterns,
advanced statistical techniques have been developed such as group-based
modeling (Nagin, 2005 ) or latent-growth curve modeling (e.g., Duncan & Duncan,
2004 ) have been utilized by researchers to identify trajectories and patterns of desistance
from crime. Very importantly, longitudinal studies conducted by at-risk samples
have shown that the adolescent-limited pattern of offending with desistance
prior to age 18 is not as common as first believed. For example, the Bushway et al.
( 2003 ) study found that a trajectory described as “bell-shape desistors,” an offending
pattern that resembled the classic age–crime curve where offending is limited
and circumscribed to the period of adolescence, comprised only 8.5 % of the sample
of at-risk youth. More specifically, for most youth included in this sample, desistance
from offending occurred after age 18. The adolescent-limited desistance type
has questionable explanatory relevance regarding desistance patterns of more serious
patterns of offending, such as chronic, violent and sexual offending.
Offending Trajectories of Individuals Involved in Sexual Offense
The interest for offending trajectories and patterns of desistance among individual
having committed a sexual offense has grown in recent years. Researchers have examined
general offending among samples of adult offenders (Francis, Harris, Wallace,