Incremental Contributions of Static and Dynamic Sexual Violence Risk Assessment: Integrating Static-99R and VRS-SO Common Language Risk Levels

• Author: Stephen C. P. Wong,Sarah M. Beggs Christofferson,Drew A. Kingston,Sharon M. Kelley,Mark E. Olver,David Thornton
• DOI: 10.1177/0093854820974400
• Date: 01 August 2021
• Published date: 01 August 2021
• Subject Matter: Articles

CRIMINAL JUSTICE AND BEHAVIOR, 2021, Vol. 48, No. 8, August 2021, 1091 –1110.

DOI: https://doi.org/10.1177/0093854820974400

Article reuse guidelines: sagepub.com/journals-permissions

© 2020 International Association for Correctional and Forensic Psychology

1091

INCREMENTAL CONTRIBUTIONS OF STATIC

AND DYNAMIC SEXUAL VIOLENCE RISK

ASSESSMENT

Integrating Static-99R and VRS-SO Common

Language Risk Levels

MARK E. OLVER

University of Saskatchewan

SHARON M. KELLEY

Sand Ridge Secure Treatment Center

DREW A. KINGSTON

HOPE Program

The Royal’s Institute of Mental Health Research

SARAH M. BEGGS CHRISTOFFERSON

University of Canterbury

DAVID THORNTON

Forensic Assessment, Training, & Research (FAsTR), LLC

STEPHEN C. P. WONG

Swinburne University of Technology

University of Saskatchewan

We examined the incremental contributions of static and dynamic sexual violence risk assessment in a multisite sample of

1,289 men treated for sexual offending. The study extends validation work that established new risk categories and recidivism

estimates for the Violence Risk Scale–Sexual Offense version (VRS-SO), using the risk assessment common language (CL)

framework. Different rates of sexual recidivism were observed at different thresholds of static risk (Static-99R) as a function

of dynamic risk and treatment change, particularly for men who were actuarially above or well above average risk (Levels

IVa and IVb, respectively). A framework integrating CL risk levels for Static-99R and VRS-SO dynamic scores into overall

AUTHORS’ NOTE: The views, opinions, and assumptions expressed in this article are those of the authors

and do not necessarily reflect the views or official positions of the University of Saskatchewan, Sand Ridge

Secure Treatment Center, the HOPE Program, University of Ottawa Institute of Mental Health Research,

University of Canterbury, or Swinburne University of Technology. Mark E. Olver, Sharon M. Kelley, and

Stephen C. P. Wong are the coauthors of Violence Risk Scale–Sexual Offense version materials; they and Sarah

M. Beggs Christofferson receive remuneration from consultation and training services with the tool. David

Thornton is the coauthor of the Static-99R and receives occasional remuneration from providing trainings on

the tool. Correspondence concerning this article should be addressed to Mark E. Olver, Department of

Psychology, University of Saskatchewan, 9 Campus Drive, Arts Building Room 154, Saskatoon, Saskatchewan,

Canada S7N 5A5; e-mail: mark.olver@usask.ca.

974400CJBXXX10.1177/0093854820974400Criminal Justice and BehaviorOlver et al. / Integrating Static-99R and VRS-SO CL Risk Levels

research-article2020

1092 CRIMINAL JUSTICE AND BEHAVIOR

CL risk levels is presented. We discuss implications for dynamic sexual violence risk assessment regarding the language used

for risk communication and the importance of dynamic risk instruments in sexual violence evaluations, particularly when

credible agents of risk change may be present.

Keywords: dynamic risk; sexual recidivism; treatment; change; Static-99R; VRS-SO

The problem of sexual violence understandably generates considerable public ire and

fear on an international scale. In turn, the people who are convicted and sentenced for

sexual offenses are subject to evaluations that may include high stakes decisions pertaining

to preventive detention (e.g., sexually violent person legislation, “dangerous offender” des-

ignation), long-term supervision, as well as community release and reintegration—all with

the goal of preventing future sexual violence. Forensic psychological evaluators are rou-

tinely called upon by decision-making bodies (e.g., courts, parole boards, forensic mental

health review boards) to assess risk of future sexual violence under circumstances in which

their clientele may have changed. Such a task requires, among other considerations over the

course of a forensic psychological evaluation, recognizing a potential change agent, detect-

ing changes relevant to risk, and incorporating such information into risk appraisals and

recommendations for risk management.

The present study examines the intersection of actuarial risk and treatment change in a

large combined multisite sample of men convicted for sexual offenses and treated for sexual

offending, building on the initial work by Olver and Wong (2011). In a Canadian correc-

tional sample of 321 men who attended a high intensity sexual violence reduction program

and who were followed up an average of 10 years postrelease, Olver and Wong (2011)

found: (a) men evaluated as high risk on a static actuarial tool who made substantive reduc-

tions in risk measured pre–post treatment had significantly lower rates of sexual recidivism

than similarly statistically high risk men who did not evidence such change, (b) men evalu-

ated as low risk who made large treatment strides and additional risk reduction did not differ

meaningfully on outcome from similarly low risk men who evidenced few gains, and (c) the

predictive accuracy of a well-established static actuarial measure of sexual violence risk,

the Static-99 (Hanson & Thornton, 1999), was comparatively weaker for men who made

substantial reductions in risk pre–posttreatment than men who had made fewer gains—pre-

sumably because the static measure no longer accurately reflected the level of sexual vio-

lence risk of high change men. The discussion and review of the literature that follows

unpacks each of these considerations with respect to credible agents of risk change, the risk

relevance of change, and the interrelation of sexual violence risk, change, and outcome; all

of which has implications for sexual violence risk assessment and management.

CREDIBLE AGENTS OF RISK CHANGE

If the men who commit sexual offenses can and do change in terms of their risk of sexual

violence and are capable of moving on to more satisfying offense-free lives, what are the

active agents of change? Although there are several viable candidates, such as advancing

age (Hanson, 2002; Thornton, 2006), declining physical health, improvements in social and

environmental supports (Burt et al., 2016), or enhanced community supervision and moni-

toring (Bonta et al., 2011; Polaschek et al., 2018), arguably evidence-informed correctional

treatment is a viable candidate. It is further anticipated that such processes may serve as an