South Carolina is one of 20 states that authorize indefinite civil commitment of sex offenders after they have completed their prison sentences. Under state law, such continued detention is allowed only when a jury concludes beyond a reasonable doubt that a respondent qualifies as a “sexually violent predator” (SVP), meaning he “suffers from a mental abnormality or personality disorder that makes [him] likely to engage in acts of sexual violence if not confined in a secure facility for long-term control, care, and treatment.”
Although the South Carolina Office of Mental Health (OMH) concluded that Andy Hyman was not an SVP, a jury disagreed, swayed by a second opinion based largely on penile plethysmography (PPG), a scientifically dubious technique that aims to measure sexual response to images, audio narratives, or textual descriptions by gauging tiny changes in the circumference of the subject’s penis. That test, the South Carolina Supreme Court unanimously ruled last month in response to Hyman’s appeal, is “generally inadmissible in judicial proceedings” because it suffers from a “glaring lack of standardization,” which casts doubt on its validity as a predictor of recidivism.
With that decision, the South Carolina Supreme Court joins a long list of state and federal courts that have deemed PPG results unreliable and inadmissible. The technique is so controversial that the OMH, which is charged with conducting pre-commitment evaluations under South Carolina’s SVP law, eschews PPG as a matter of policy. But the state is allowed to solicit a second evaluation if it does not like the OMH’s opinion, which is what happened in Hyman’s case.
Hyman, who pleaded guilty to criminal sexual conduct with a minor in 1997, served “a short term in prison” and “completed several years of supervised release in 2003,” the South Carolina Supreme Court noted. Thirteen years later, Hyman pleaded guilty to the same crime, this time in the third degree, which resulted in a 10-year prison sentence. Before he completed that sentence, the state sought to continue detaining him as an SVP.
Marie Gehle, the OMH’s chief psychologist, conducted “a series of standardized tests” and diagnosed Hyman with “pedophilic disorder.” But she concluded that he did not fit the statutory criteria for civil commitment because he was not especially likely to reoffend. Unsatisfied with that assessment, the state asked Emily Gottfried, director of the Sexual Behavior Clinic and Lab at the Medical University of South Carolina (MUSC), for a second opinion.
Gottfried agreed that standardized tests placed Hyman “squarely within the average rate of recidivism” for sex offenders. But unlike Gehle, she also conducted a PPG test, which seemed to play an important role in her conclusion that Hyman posed “a heightened risk of reoffending.”
During the trial, Gottfried described PPG as “an objective physiological measure of male sexual arousal,” “the gold standard” for assessing that response, and a “strong predictor or risk factor for future sexual offending.” The PPG results, the state’s lawyer told the jury, “clearly indicate[d]” that Hyman had a “current sexual interest in children.” That was enough, “in and of itself,” to justify his civil commitment, the state argued.
The jury deliberated for just 22 minutes before agreeing with Gottfried. It rejected the contrary assessment offered by Gehle, who testified that most of the tests Gottfried had used were not designed to measure the likelihood of recidivism. In particular, Gehle said, PPG is not reliable, since retests produce inconsistent results, or valid as a predictor of future offending, which she said is why the OMH does not use it for pre-commitment evaluations.