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Sexual Violence Risk-20

Sexual Violence Risk-20


The Sexual Violence Risk-20, also called the SVR-20, is an assessment instrument used by mental health professionals.


The SVR-20 provides a structure for reviewing information important in characterizing an individual's risk of committing sexual violence and for targeting plans to manage that risk. The instrument's authors define sexual violence as, "Actual, attempted or threatened sexual contact with a person who is non-consenting or unable to give consent."


SVR-20 results should be finalized and interpreted by a professional who is familiar with the scientific literature on sexual violence, and who is experienced in conducting individual assessments on sexual and violent offenders. The instrument is not capable of providing new information about past behavior or of profiling an examinee as a sexually violent offender. Rather, it helps provide a structure to follow in estimating risk of sexual violence under certain circumstances. The instrument should not be used as a stand-alone measure, and predictions derived from its use should be subject to critical review. It is especially important to place results in the contexts of the examinee's personal style, likely environmental conditions, and base rates of sexual violence in other offenders with similar characteristics.


The SVR-20 is a tool that helps guide a professional in conducting a minimally comprehensive assessment of sexual violence risk. The assessment process is based on six principles:

  • It is important to gather a depth of information about the examinee's personal, social, occupational, mental health, illegal, and other relevant behavior.
  • Information should be gathered using a variety of sources and methods, including (and not limited to) record reviews, interviews, and psychological, physiological, and medical techniques.
  • Information should be gathered from the examinee, his or her relatives and acquaintances, the victim(s), professionals who have interacted with the examinee, and any other sources likely to yield useful information.
  • The examinee's history and future exposure to risk factors should be considered.
  • The examiner should critically weigh the accuracy, credibility and applicability of the data that has been gathered.
  • The risk assessment process should be ongoing, with regular re-assessments for many examinees.

The content of the SVR-20 was developed following a comprehensive review of similar instruments and of the scientific literature on risk for sexual violence and re-offense. The SVR-20 materials consist of a reference manual and protocol sheets that are filled out by the examiner. The instrument includes three major sections: Psychosocial Adjustment, Sexual Offenses, and Future Plans. The SVR-20 items are coded based on presence (Yes or No) and if present, whether there has been a recent change in status regarding that factor (Exacerbation, No Change, Amelioration).

The Psychosocial Adjustment section includes 11 risk factors: sexual deviation, victim of child abuse , psychopathy, major mental illness, substance use problems, suicidal/homicidal ideation (ideas), relationship problems, employment problems, past non-sexual violent offenses, past non-violent offenses, and past supervision failure.

The Sexual Offenses section includes seven risk factors: high-density sex offenses, multiple sex offense types, physical harm to victim(s) in sex offenses, escalation in frequency and severity of sex offenses, extreme minimization or denial of sex offenses, and attitudes that support or condone sex offenses.

The Future Plans section includes two factors: lacks realistic plans, and negative attitude toward intervention . Aside from factors related to the examinee's thinking and personality, items found in the first and second sections reference fixed or relatively stable characteristics.

The first and third sections are relevant not only to sexual violence, but also to violence in general. There is also an unstructured supplementary section entitled "Other Considerations," that can be used to describe unique factors relevant to an examinee's probability of risk.


The SVR-20 does not allow for the definite prediction of sexual violence. Prediction of risk is summarized using a rating of low, moderate or high. Although the instrument's authors did not provide decision-making guidelines for determining the appropriate rating, they did recommend five questions to consider in communicating a "Risk Message" derived from the results:

  • What is the likelihood that the individual will engage in sexual violence, if no efforts are made to manage the risk?
  • What is the probable nature, frequency, and severity of any future sexual violence?
  • Who are the likely victims of any future sexual violence?
  • What steps could be taken to manage the individual's risk for sexual violence?
  • What circumstances might exacerbate the individual's risk for sexual violence?

Typically, answers to these and other questions are fashioned in the form of a report for those responsible for making decisions about the examinee.



Boer, D., S. Hart, P. Kropp, and C. Webster. Manual for the Sexual Violence Risk-20. Burnaby, British Columbia, Canada: The British Columbia Institute Against Family Violence, co-published with the Mental Health, Law, and Policy Institute at Simon Fraser University, 1997.

Laws, D., and W. O'Donohue. (Eds.) Sexual deviance: Theory, assessment and treatment. New York: Guilford, 1997.

Marshall, W., D. Laws, and H. Barbaree. (Eds.) Handbook of Sexual Assault: Issues, theories, and treatment of the offender. New York: Plenum Press, 1990.


Menzies, R., and C. Webster. "Construction and validation of risk assessments in a six-year follow-up of forensic patients: A tridimensional analysis." Journal of Consulting and Clinical Psychology 63 (1995): 766-778.

Monahan, J. "Mental disorder and violent behavior." American Psychologist 47 (1992): 511-521.


American Psychological Association. 750 First Street, NE, Washington, DC 20002-4242. Telephone: (800) 374-2721. <>.

Association for the Treatment of Sexual Offenders. 4900 S.W. Griffith Drive, Suite 274, Beaverton, Oregon 97005. Telephone: (503) 643-1023. <>.

British Columbia Institute Against Family Violence, 409 Granville Street, Suite 551, Vancouver, BC V6C 1T2. Telephone: (604) 669-7055 or Toll free (Canada): (877) 755-7055. <>.

Geoffrey G. Grimm, Ph.D., LPC

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