Offenders with Intellectual Disability


Defendants with intellectual disability are at a relative disadvantage during the Court process. may qualify for consideration of the insanity defence, or they may be rendered unfit to stand trial by their disability. The disposal of defendants found fit or insane due to an intellectual disability is governed by the Intellectual Disability (Compulsory Care and Rehabilitation) Act 2003.

Section 7 of the ID(CCR) Act states:

“Meaning of intellectual disability

(1) A person has an intellectual disability if the person has a permanent impairment that—

  1. results in significantly sub-average general intelligence; and
  2. results in significant deficits in adaptive functioning, as measured by tests generally used by clinicians, in at least 2 of the skills listed in subsection (4); and
  3. became apparent during the developmental period of the person.

(2) Wherever practicable, a person’s general intelligence must be assessed by applying standard psychometric tests generally used by clinicians.

(3) For the purposes of subsection (1)(a), an assessment of a person’s general intelligence is indicative of significantly sub-average general intelligence if it results in an intelligence quotient that is expressed—

  1. as 70 or less; and
  2. with a confidence level of not less than 95%.

(4) The skills referred to in subsection (1)(b) are—

  1. communication:
  2. self-care:
  3. home living:
  4. social skills:
  5. use of community services:
  6. self-direction:
  7. health and safety:
  8. reading, writing, and arithmetic:
  9. leisure and work.

(5) For the purposes of subsection (1)(c), the developmental period of a person generally finishes when the person turns 18 years.”

Fetal Alcohol Spectrum Disorders may cause mental disability even with an IQ in the normal range, as in the case of Teina Pora v The Queen (New Zealand)  (