Court of Appeals holds results of a penile plethysmograph (PPG) test are inadmissible as unreliable

I typically don’t blog about criminal cases and In the Matter of Shawn T. Daily, 443 S.C. 557, 905 S.E.2d 310 (Ct.App. 2024), may still get altered by the Supreme Court, but the June 12, 2024 Court of Appeals opinion in this case has impact on issues in family court.

Daily involved the admissibility of a penile plethysmograph (PPG) test.  The test shows the participant various stimuli (typically visual or auditory) while monitoring blood flow to the participant’s penis. The intended purpose of a PPG is to determine what the participant finds sexually stimulating.  In Daily, the circuit court considered, over Daily’s object, the results of his PPG test in deciding to place him on involuntary commitment under the Sexually Violent Predator Act. Daily appealed the use of the test in making that determination.

The Court of Appeals reversed the circuit court and remanded for a new hearing.  Citing In the Matter of Bilton, 432 S.C. 157, 851 S.E.2d 442 (Ct. App. 2020), the Court of Appeals held, “the test is controversial and has been criticized for a lack of standardization and for being subject to manipulation… Courts have noted that PPGs are routinely used as a tool in treatment programs and with limited exceptions courts have uniformly declared that PPG test results are inadmissible as evidence because there are no accepted standards for this test in the scientific community.”

The family courts often use the PPG as a diagnostic tool in DSS sexual abuse cases and sometimes use them in custody cases.  However, unless the Court of Appeals or Supreme Court ultimately overturns the Court of Appeals ruling in Daily, it is very unlikely a family court will consider PPG test results over one party’s objection.