Neuropsychology, neuroscience, volitional impairment and sexually violent predators: A review of the literature and the law and their application to civil commitment proceedings

The U.S. Supreme Court held in Kansas v. Crane, the person's mental abnormality or personality disorder must cause the individual to have “serious difficulty in controlling his sexual behavior,” rather than “total or complete lack of control.” While most state civil commitment statutes do not mandate this volitional impairment language relevant to loss of control, they instead incorporate the requirement of findings of “likely” or “likelihood” to reoffend. Yet in some of these state SVP hearings, the forensic mental health expert witnesses testify as to the offender's ability to control his sex offending behaviors. Occasionally, some of these experts are neuropsychologists and neurologists who testify about a sex offender's neurological and cognitive impairment resulting in sexually deviant behavior, volitional impairment, and likelihood of reoffending. This article's focus is to assess deviant sexual offending behaviors and volitional impairment through a neuropsychological and neurological lens. The author will provide an analysis of the literature as to the structural and functional neurocognitive processes of sex offending pertaining to neuropathology, neuropsychology, and neuroimaging data. The author will attempt to apply these findings to the legal requirements outlined in Crane necessitating commitment of sex offenders who experience some volitional impairment in their behaviors that lead them to be likely to sexually reoffend. The author will review state case law addressing neuroscience in SVP proceedings.

► Sex offenders often have brain damage and neurodevelopmental abnormalities.
► Subcortical and prefrontal cortex brain structures are indicated in sexual deviance.
► Neuroscience may add evidence to volitional impairment in sex offenders.