The cohorts were found to be similar in age and tested IQ levels. Early psychiatric services were more likely in the lower security groups. As predicted, mental disorders in combination with intellectual impairment were more likely in the high-security cohort. Comorbid personality disorders were prevalent in this cohort. Convictions for violent offenses and a history of violence were more common in the high-security group. Over 50 percent of the offenders in all of the cohorts had at least one conviction for a sexual offense. For such offenses, those in the high-security and low/medium security cohorts had used weapons; whereas those in the community-service cohort had not. The high-security facility is the only facility for offenders in England and Wales that receives intellectually disabled individuals from prisons, secure hospitals, and the courts. It houses patients deemed to be a serious and immediate danger to the public. The low/medium-security establishment consists of seven forensic units and wards. Rehabilitation services and inpatient forensic services are provided. The community-service cohort resided in a 10-bed open facility where they were housed when not performing community service sentences. A variety of treatment options are also offered. 5 tables and 29 references