Sex Offenders With and Without Intellectual Disability: Clinical, Behavioral, and Criminal Characteristics

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Individuals with intellectual and developmental disabilities (IDD) who have committed sexual offenses are a diverse group with complex needs. Because of the nature of their deficits in communication, adaptive skills, social relationships, and cognitive capacity, such individuals may be more likely to be arrested, to confess, to be found incompetent to proceed, to plead guilty, or to be sentenced to a secure facility in response to criminal activity. Understanding the quantifiable differences between sexual offenders with and without IDD could inform and improve policies around the allocation of resources for prevention and treatment efforts for offenders with IDD. The current study seeks to elaborate on our understanding of the characteristics of sex offenders with IDD in comparison with cognitively-normal sexual offenders. A total of 245 patients with and without IDD residing in a secure forensic psychiatric hospital were selected. The sample is predominantly male (90.6%, n=222) and majority Caucasian (53.5%, n=131), African American (42.9%, n=105), and Hispanic (1.6%, n=4) with a mean age of 39.2 (SD=12.0). Participants range from persons with normal cognitive functioning (42.0%, n=103) to those with borderline intellectual functioning (17.1%, n=42), traumatic brain injury (10.2%, n=25), pervasive developmental disability (6.9%, n=17), fetal alcohol syndrome (3.7%, n=9), and IQ scores falling within the range of moderate (4.9%, n=12) and mild (15.1%, n=37) mental retardation. Participants with IDD presented with significant histories of childhood maltreatment and adversity (e.g., neglect), previous institutionalizations and out-of-home placements, and diagnosed impulse control disorders, psychotic disorders, and personality disorders. Generally, individuals with IDD were reported to express deviant sexual behavior in non-contact formats (i.e., sexual behavior that did not result in the victim being physically touched) more so than non-IDD individuals. Further, rates of deviant behavior were comparable between the two groups within community settings. However, while in residential settings those with IDD exhibited significantly more behaviors (p=0.044) than those without IDD. For the most part, the current empirical literature seemingly overlooks individuals with IDD residing in secure forensic settings. Particularly, little focus is given to the differences and similarities between individuals with various types of IDD. Understanding the clinical, behavioral, and criminal characteristics of this population could have valuable implications for the diagnosis, treatment, and rehabilitation of offenders with IDD.


Johnson City, TN

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