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Sexually Violent Person Statutes Differ Considerably Throughout the United States

Forensic Training AcademySVP statutes differ on definitional and procedural grounds, contributing to misapplication and misinterpretation by clinicians, policymakers, and courts. This is the bottom line of a recently published article in International Journal of Forensic Mental Health. Below is a summary of the research and findings as well as a translation of this research into practice.

International Journal of Forensic Mental HealthFeatured Article | International Journal of Forensic Mental Health | 2015, Vol. 14, No. 4, 245-266

A National Survey of United States Sexually Violent Person Legislation: Policy, Procedures, and Practice


David DeMatteo, Department of Psychology and Thomas R. Kline School of Law, Drexel University, Philadelphia, Pennsylvania, USA
Megan Murphy, Department of Psychology and Thomas R. Kline School of Law, Drexel University, Philadelphia, Pennsylvania, USA
Meghann Galloway, Department of Psychology and Thomas R. Kline School of Law, Drexel University, Philadelphia, Pennsylvania, USA
Daniel A. Krauss, Department of Psychology, Claremont McKenna College, Claremont, California, USA


Sexually Violent Person (SVP) commitment statutes provide for indeterminate civil confinement of certain sex offenders after completion of their criminal sentences. In the United States, SVP laws raise important concerns relating to due process, ex post facto claims, and protection against double jeopardy. However, it is unclear to what extent current legislation addresses or neglects these issues. Without a systematic review of SVP legislation and related case law, it remains unknown to what degree U.S. states have incorporated different strategies to protect individual rights outlined by the U.S. Supreme Court. In this study, SVP statutes from each U.S. state, the federal government, and the District of Columbia, along with related case law, were examined to evaluate (1) the requirements of SVP confinement, (2) the procedures by which SVP hearings occur, and (3) the degree to which the requirements enumerated by the U.S. Supreme Court have been followed.  Although nearly half of all states have SVP statutes, findings reveal that statutes differ considerably regarding standards of proof, commitment procedures, appeals standards, definitions of important terms, and procedural safeguards. Moreover, case law provides important information on how SVP laws actually operate. Findings are discussed in light of psychological, legal, and policy implications.


sexually violent person, sexually violent predator, legislation, statute

Summary of the Research

“Sexually Violent Person (SVP) laws (or Sexually Violent Predator laws) provide for the indeterminate post-incarceration confinement in psychiatric facilities of individuals who are identified as likely to reoffend sexually. Today, slightly less than half of all U.S. states and the federal government have enacted some form of SVP statute. Most SVP commitment statutes require that the state prove at least three elements: (1) the defendant was convicted of or charged with a sexual offense, (2) the defendant has a mental disorder or abnormality, and (3) the defendant is likely to engage in sexually violent behavior in the future.  Despite similarities in terms of legislative purpose, SVP statutes differ considerably across jurisdictions” (p. 245). “The purpose of this study was to identify and catalog the SVP commitment statutes in U.S. states that have adopted this form of civil confinement. After identifying the SVP commitment statutes in each state that has enacted such a law, we compared the statutes on various elements” (p. 249).

“Using comprehensive electronic legal databases, we conducted a survey of state and federal SVP commitment laws, and related case law, in the United States. Two advanced graduate students with legal training coded each SVP statute on 18 elements: procedures for determining volitional impairment or serious difficulty controlling behavior, whether the definition of mental illness included personality disorders and paraphilias, definition of “likely,” burden of proof for commitment, standard of proof for release, age limitations, existence of a probable cause hearing, evidentiary admissibility standard, appellate standard of review, trial procedures, existence of an automatic appeal, enactment date, location of trial/hearing, parties who can request a jury trial, whether actuarial instruments are required, whether previous sexual conduct is required, whether a low probability of recidivism but high degree of sexual offense severity is allowed in the definition of “likely”, and whether individuals determined to be SVP are granted confidentiality… Because courts are responsible for interpreting the SVP statutes enacted by the legislature in the context of specific cases, we also examined case law in all jurisdictions with SVP statutes. Only examining statutes could be misleading because it does not provide information on how the SVP laws actually operate. Given the volume of SVP cases across jurisdictions, we focused on cases decided by the highest court in each jurisdiction, and four students with training in reading and interpreting case law identified how the courts interpreted the various elements of the SVP statutes.” (p.249)

“The results of this legislative survey suggest that, in many aspects, states with SVP statutes have modeled their statutes after the statute upheld in Kansas v. Hendricks  (1997)… [however], there are significant definitional differences across jurisdictions” (p.253). “The failure to adequately define this term limits its usefulness in terms of narrowing the class of individuals targeted by SVP laws” (p.253).

“Statutes also differ considerably regarding the operationalization of “likely” to engage in future sexual offenses” (p.253). “The ambiguity or complete absence of clarification is problematic in light of the perception of jurors left unguided by instruction… in effect, absent any specification some jurors would find that all individuals facing commitment are “likely” to recidivate. Once again, this calls into question how significantly this requirement narrows the class of individuals targeted by these laws” (pp. 253-254).

“Procedurally, states have enacted vastly different SVP commitment statutes. For example, states differ greatly regarding the inclusion/exclusion of juveniles in SVP commitment…The long-term detention of juveniles, combined with the vulnerability of juveniles and the labeling effect that may occur by designating a juvenile as an SVP, could produce unintended negative consequences…Given that the majority of state SVP laws are silent regarding the inclusion of juveniles, state legislatures are encouraged to clarify whether juveniles in their jurisdictions are subject to SVP commitment” (p. 254).

“Additionally, states are split regarding burden of proof necessary for SVP commitment. Nine states require clear and convincing evidence and 10 states require evidence beyond a reasonable doubt for SVP commitment. Three states require a lower burden of proof to be released from SVP confinement than what is needed to be committed. Two states do not specify a burden of proof necessary for SVP release and instead rely on unique criteria for SVP release. One state is silent regarding the burden of proof necessary to be released from SVP confinement. It is unclear the extent to which the standard of proof actually impacts the decision-making of jurors… It is likely jurors would need additional guidance to understand and quantify what exactly constitutes a particular level of proof” (p. 254).

“States also differ procedurally in terms of probable cause hearings… it is unclear how a jury would impact the outcome of SVP commitment proceedings because jurors are less likely to have a sophisticated understanding of recidivism risk and treatment amenability, and they may have strong prejudices against sexual offenders” (p. 254).

“States also differ considerably regarding reliance on psychological evaluations and assessments. Three states require the use of psychological instruments during SVP proceedings. Some states require psychological assessment to aid in determining whether an individual has a mental abnormality that makes them likely to engage in repeat acts of sexual violence, while other states require the use of psychological assessments as a screening method for SVP consideration” (p. 254).

“States have adopted widely varying definitions and procedures for SVP commitment. Many of these statutes are vague or silent regarding important definitional or procedural elements, such as “mental abnormality,” determination of “likely,” inclusion of juveniles, and the existence of probable cause hearings. This could result in misapplication and misinterpretation of SVP laws by the courts. Moreover, extremely vague and ambiguous language can be unconstitutional” (p. 254).

Translating Research into Practice

“Because of the significant differences among state SVP statutes, clinicians must be familiar with the SVP laws in their jurisdiction because even minor terminology differences could impact SVP determinations…Addressing the proper legal standard in an SVP case is particularly important due to the significant deprivation of liberty that is at stake. At a minimum, clinicians should know the definition of “mental abnormality” used in their jurisdiction and how “likely” to reoffend sexually is defined. Clinicians should also know whether the definition of mental abnormality includes personality disorders and paraphilias. This familiarity entails knowledge of statutory definitions and case law that may have modified the definitions” (p.255).

“As with any forensic mental health assessment, clinicians must utilize procedures and psychological assessments that will withstand judicial scrutiny… several of the psychological measures commonly used in SVP evaluations have been shown to be problematic because the measures are not relevant to the determination of whether someone is an SVP” (p.255)

“To comply with relevant professional standards, evaluators reporting sex offender risk assessment results should convey the results in a manner that accurately portrays group-related risk information, measurement error, and potential threats to validity…Specifically, risk assessment results should include the specific outcome, over a specific period of time, in a specific population. Mental health professionals conducting SVP evaluations must be familiar with the limitations of psychological tests and only use instruments that are well validated and appropriate for the SVP context” (p.255).

“Because base rates are essential to prediction models, the absence of reliable base rates, or the neglect of known base rates, impairs an evaluator’s ability to predict the likelihood of future offending behavior. As such, evaluators should clearly explain all accuracy limitations and be prepared to discuss these limitations in court” (p.255).

“For mental health practitioners, it is essential that evaluators understand the relevant definitions, procedures, and standards for SVP commitment in their jurisdiction and conduct evaluations using reliable procedures. This is particularly important in light of the limited clarification from lawmakers and the resulting potential for both scientifically rigorous and poorly conducted evaluations. Practitioners must take some degree of responsibility for refraining from accepting improper evaluation requests. For legislators, it is crucial to recognize that incomplete and/or vague SVP statutes can contribute to potential misapplication and misinterpretation by the courts, which is particularly undesirable when there are such significant liberty interests at stake” (p.256).

Other Interesting Tidbits for Researchers and Clinicians

“The majority of states include personality disorders in their SVP commitment laws. The inclusion of personality disorders within the mental abnormality component is problematic because it goes beyond traditional notions of civil commitment, which was originally designed for mental health disorders not classified as personality disorders. Including individuals with personality disorders in effect captures the majority of individuals facing SVP commitment, particularly because 40%–80% of male prison inmates meet criteria for Antisocial Personality Disorder. This raises the concern of whether SVP commitment is really limited to a “subclass of dangerous offenders” in accordance with constitutional requirements” (p.253)

“The treatment of SVPs could be significantly improved by using evidence-based treatment models. The Supreme Court in Hendricks stated that states may be obligated to provide available treatment for treatable disorders, although the Court made it clear that effective treatment is not required to justify civil commitment. Unfortunately, there is a dearth of research on successful therapy addressing sex offending specifically, and it is not clear what would constitute “effective” therapy, but this should elicit more research rather than more restrictions. Perhaps a straightforward and easily assessed metric of effective therapy would be reductions in recidivism, and this is an area that is ripe for research. Additionally, commitment should be based on risk factors supported by research rather than in response to public fears” (p.256).

Join the Discussion

As always, please join the discussion below if you have thoughts or comments to add!

Megan BanfordAuthored by Megan Banford

Megan Banford is a master’s student in the Forensic Psychology program at John Jay College. She graduated in 2013 from Simon Fraser University with a B.A. (Honors) and hopes complete a PhD in clinical forensic psychology. Her main research interests include violence risk assessment and management, juvenile offenders and public policy.

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