South Carolina Supreme Court Rules Penis Measurement Test Inadmissible in Sex Offender Commitment Cases

The South Carolina Supreme Court issued a unanimous ruling last month declaring that penile plethysmography (PPG) — a test that measures changes in penile circumference in response to sexual stimuli — is generally inadmissible in court proceedings due to a 'glaring lack of standardization' and unreliable results. The case centered on Andy Hyman, who had twice pleaded guilty to criminal sexual conduct with a minor and was facing indefinite civil commitment as a sexually violent predator before completing his second prison sentence. The South Carolina Office of Mental Health's chief psychologist evaluated Hyman and concluded he did not meet the legal criteria for civil commitment, finding his recidivism risk to be average. The state then sought a second opinion from a researcher at the Medical University of South Carolina, who administered a PPG test and concluded Hyman posed a heightened reoffending risk, calling PPG the 'gold standard' for measuring sexual arousal. A jury deliberated just 22 minutes before siding with the second expert and ordering Hyman's indefinite commitment. The Supreme Court's ruling joins a growing body of state and federal decisions rejecting PPG evidence, and notably aligns with the policy of South Carolina's own Office of Mental Health, which does not use PPG in its evaluations.