Background There is a need for research to promote an understanding among service developers on why people with intellectual disabilities (ID) are referred to offender services in order for them to receive appropriate assessment and treatment. Previous studies investigating referrals into forensic ID services have concentrated on referral sources and administrative variables such as legal status. Aims To construct a predictive model for choice of service referral based on a comprehensive range of information about the clientele. Method We conducted a case record study of 336 people referred to community services and 141 to secure provision. We gathered information on referral source, demographics, diagnosis, index behaviour, prior problem behaviours and history of abuse. Results Comparisons revealed 19 candidate variables which were then entered into multivariate logistic regression. The resulting model retained six variables: community living at time of referral, physical aggression, being charged, referral from tertiary health care, diverse problem behaviour and IQ <50, which correctly predicted the referral pathway for 85.7% of cases. Conclusions An index act of physical aggression and a history of diversity of problem behaviours as predictors against the likelihood of community service referral suggest that professionals have similar concerns about people with ID as they do about their more average offending peers; however, the more severe levels of ID mitigated in favour of community referral, regardless. Offenders with ID tend to be referred within levels of service rather than between them, for example, form tertiary services into generic community services.