Encyclopedia of Psychology and Law

In W. L. Marshall, D. R. Laws, & H. E. Barbaree (Eds.),

Handbook of sexual assault: Issues, theories, and

treatment of the offender (pp. 363–385). New York:

Plenum.

Prentky, R., Lee, A., Knight, R., & Cerce, D. (1997). Recidivism

rates among child molesters and rapists: A methodological

analysis. Law and Human Behavior, 21,635–659.

SEXOFFENDERRISK

APPRAISALGUIDE (SORAG)

The Sex Offender Risk Appraisal Guide (SORAG) is

a 14-item actuarial scale designed to predict violent,

including hands-on, sexual recidivism among men

who have committed at least one previous hands-on

sexual offense.

The items on the scale are the following:

1. Lived with both biological parents until age 16


2. Elementary school maladjustment


3. History of alcohol problems


4. Never been married at time of index offense


5. Criminal history score for nonviolent offenses


6. Criminal history score for violent offenses


7. Number of convictions for previous sexual offenses


8. History of sexual offenses only against girls below
   14 years of age (negatively scored)


9. Failure on prior conditional release


10. Age at index offense (negatively scored)


11. Diagnosis of any personality disorder


12. Diagnosis of schizophrenia (negatively scored)


13. Phallometric test results indicating deviant sexual
    interests


14. Psychopathy Checklist (Revised) score

Each item is scored and then assigned a weight

based on the relationship of that item to violent recidi-

vism in the construction sample; the weights are then

summed to obtain a total score. The score yields the

percentile rank of the offender as compared with the

construction sample and the estimated probability of

violent recidivism based on a 7- and a 10-year period

of opportunity to re-offend. The items can be scored

from complete institutional files or from files and

interviews (but note that external corroboration of

offender self-report is important).

The initial construction sample used by Rice and

Harris in 1997 comprised released child molesters and

rapists who had been briefly assessed in a Canadian

maximum security psychiatric hospital before transfer

to corrections and offenders treated in the psychiatric

institution. Outcome data were obtained from a vari-

ety of official sources, and criminal charges for vio-

lent or hands-on sexual crimes were the primary

predicted outcome. Outcome data were collected by

individuals blind to offenders’ SORAG scores.

The SORAG is closely related to the Violence Risk

Appraisal Guide (VRAG), an instrument designed to

predict violent recidivism among serious offenders

(not exclusively sex offenders), and it contains many

of the same items. Accuracy of predicting recidivism

is similar in the two instruments among sex offender

samples, but the estimated probability of recidivism is

higher for the SORAG (reflecting the fact that sex

offender samples have higher violent and sexual

recidivism rates than unselected samples).

Follow-up studies of sex offenders using the

SORAG have examined variations in sample (correc-

tional releasees, forensic psychiatric hospital releasees,

offenders supervised in the community), jurisdiction

(Canada, United States, Europe), and variations in aver-

age follow-up time. The SORAG has been robust to

these variations, and SORAG scores are consistently

linearly related to an offender’s probability of violent

recidivism. In replication studies, the accuracy of pre-

diction as indexed by the area under the curve of the

receiver operating characteristic or, equivalently, the

common language effect size is about .75, meaning that

75% of randomly selected violent recidivists have

higher SORAG scores than randomly chosen men who

are not violent recidivists. Accuracy is degraded when

recidivism is measured poorly, when data are missing

for SORAG variables, and when the length of the fol-

low-up period varies widely across offenders. In 2003,

Harris and colleagues found that, under optimum con-

ditions, an accuracy of about .85 can be achieved.

Scores on the SORAG correlate with both the speed

and severity of recidivistic offenses.

The SORAG has also been used to estimate the like-

lihood that an offender will recidivate with a specifically

sexual offense, although these offenses are a subset of

the violent offenses that the SORAG was designed to

predict. In 2006, Rice, Harris, Lang, and Cormier found,

Sex Offender Risk Appraisal Guide (SORAG)——— 729

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