Bill Lindsay presented a review of research related to pathways into and through forensic Intellectual Disability services. In his follow up studies of Community Forensic ID services (12 and 20 years) he found distinct trends in referral patterns with more recent cohorts being significantly younger and more likely to come from the criminal justice system.
He goes on to say sex offenders are older than other types of referrals (mostly violent) and men outnumber women 5 to 1. His recent research reviewed referrals to different levels of security finding that aggression and violence, referral source, diversity of offending behaviour, criminal justice involvement and IQ all predict where someone will be referred.
Surprisingly, some variables commonly associated with forensic ID such as arson and sex offending do not predict referral pathways. He has found that security levels have only a small to medium, but nevertheless significant, relationship with assessed risk.