Although some evidence exists that child molesters may be characterized by structural and functional brain abnormalities, findings across studies are inconsistent. Past cognitive research in this area has been extensively criticized for relying on conceptually weak batteries, measures of questionable reliability, and poorly defined samples (i.e., failing to distinguish between pedophilic and nonpedophilic child molesters). The present study aimed to address the weaknesses of past research by comparing 40 child molesters (20 pedophilic and 20 nonpedophilic) and 20 demographically matched nonoffender controls on six well-defined neurocognitive composite scores of comparable reliability (i.e., semantic knowledge, executive functioning, processing speed, motor speed, auditory memory, and visual memory). Results indicated that pedophilic child molesters exhibit slower processing speed, nonpedophilic child molesters exhibit poorer semantic knowledge, and both molester groups exhibit executive weaknesses as compared to nonoffender controls. This study is the first to compare the two molester types on neurocognitive functions. The observed differences between the molester groups help explain inconsistencies in past research and demonstrate the need to distinguish between the two types of child molesters when studying neurobiologic underpinnings of sexual offending. (JINS, 2009, 15, 248–257.)

The association between intellectual disability and offending is complex. Recent evidence would suggest that the received wisdom of intellectually disabled persons being more prone to offending is either incorrect or only tells part of the story. Those within the ‘borderline’ intellectual disability range may be more prone to committing sexual and criminal damage offences but those with an IQ less than 50 rarely offend.

The offender with intellectual disability shares characteristics with his counterpart from the general population. As with the general population as a whole, offending in this group is often unreported and its recognition is complicated by issues of competence. The lack of validated forensic assessment schedules for this population poses a further challenge. Some general approaches to assessment in this population are discussed. This case report illustrates the difficulties of assessing and managing offending behaviour in an individual with moderate intellectual disability. The challenge of treating offenders with an intellectual disability is immense and requires specialist expertise. Managing such cases in a generic setting is inappropriate and the need for a forensic learning disability service in Ireland is highlighted.