actuarial method eliminates human judgment about the
selection of relevant assessment information and about
how to combine that information—assessment results
depend only on empirically measured relationships
between data and the outcome of interest. Several well-
validated and replicated actuarial assessments have been
developed for use among adjudicated adult sex offend-
ers—men in custody for sexual assaults against women
or children. Consequently, psychologists could not
defend failing to use such a tool in assessing the risk of
recidivism for such sex offenders.
A few psychologists have claimed that instructing
clinicians to insert an idiosyncratically determined
amount of unaided clinical intuition at the end of the
assessment process confers an advantage in predictive
accuracy, and they have promulgated nonactuarial
schemes for doing so with sex offenders. This promul-
gation was accompanied by no evidence in support of
these claims. The few studies that have since examined
these claims among sex offenders show little evidence
overall of an improvement due to the addition of
unaided clinical intuition, which rather appears to
worsen assessment reliability when applied to offenders
in general. Because of the overwhelming evidence
against the use of unaided clinical intuition in general
and the ready availability of actuarial systems for sex
offenders, use of such schemes could not be recom-
mended. It should be noted that no actuarial systems
have been developed specifically for juvenile sex
offenders. However, some of the samples on which the
existing actuarial assessments are based included sex
offenders who were adolescents at the time of their
referral offenses, even though they were adults when
followed up. Structured schemes for juvenile sex
offenders have been published with some evidence of
predictive accuracy.
The available actuarial assessments for sex offender
recidivism are moderately to highly intercorrelated,
meaning that they do not rank order sex offenders iden-
tically. Some of this apparent disagreement is due to dif-
ferences in the operational definition of recidivism. That
is, some researchers have designed actuarial systems to
predict only those recidivistic sex offenses labeled as
such on police rap sheets. This research strategy is
known to miss some officially detected sex offenses,
especially the most serious ones (i.e., those involving
homicide). It is clear, nevertheless, that the predictive
accuracy of all these actuarial systems derives princi-
pally from two domains. The first of these was dis-
cussed earlier—deviant sexual preferences assessedphallometrically or as indicated by aspects of sex
offenders’ offending history (prior sex offenses, multi-
ple sexual victim categories, unrelated and stranger vic-
tims, clinical evidence of other paraphilias, etc.).
The second and even more powerfully predictive
domain is life-course-persistent antisociality. The best
single measure of this for forensic practice is the Hare
Psychopathy Checklist (PCL–R), which is an item in
some of the available actuarial systems for sex offend-
ers. Other characteristics (some of which are also eval-
uated in the PCL–R) indicative of this crucial forensic
risk assessment construct are a history of criminal and
violent offending; parents’ criminality and substance
abuse; early age of onset for sexually aggressive, vio-
lent, and criminal conduct; aggression and antisocial
behavior as a child; disrupted and disturbed family
background; failure on prior conditional release; sub-
stance abuse; antisocial friends and associates; poor
employment stability; hostile and selfish attitudes; quit-
ting or being ejected from sex offender treatment; and
meeting the diagnostic criteria for conduct disorder or
antisocial personality disorder. Considerable clinical
skill is required to assess some of these, but the manner
of the assessment and the combination of individual
measures should be determined entirely by an actuarial
system. Note that these constructs are somewhat redun-
dant, so that an optimal actuarial system need only cap-
ture some of them. Instructions on the scoring and
interpretation of actuarial risk assessment systems for
sex offenders are provided in the recommended read-
ings or suggested related entries.Conclusions
The sex offenders of greatest forensic concern are those
men who sexually assault children and those who
engage in sexually coercive offenses against women.
There is no accepted scientific explanation of these
criminal behaviors and no useful data on specifically
what personal or circumstantial changes caused by
intervention affect the likelihood of such behavior. As a
result, forensic clinicians can rely on very little empiri-
cal data to guide assessment when designing treatment.
Nevertheless, sufficient evidence exists to show that
greatest priority in clinical assessment should be given
to comprehensive information on the age, sex, and rela-
tionship to all victims; substance abuse; access to
potential victims; deviant sexual preferences; and vari-
ous measures indicative of life-course-persistent antiso-
ciality (especially the Hare PCL–R). Available actuarialSex Offender Assessment——— 719S-Cutler (Encyc)-45463.qxd 11/18/2007 12:44 PM Page 719