The compatibility of diminished responsibility with the Convention on the Rights of Persons with Disabilities

Article 12 of the Convention on the Rights of Persons with Disabilities (CRPD) provides that a person with a disability has an equal right to legal capacity. The right to legal capacity means that a person’s decisions are legally recognised on the same basis as others. This right is essential to ensuring that persons with disabilities can fully and effectively participate in society. The interpretation of Article 12 by the Office of the High Commissioner for Human Rights and the Committee on the Rights of Persons with Disabilities indicate that significant changes are needed to criminal law to comply with the CRPD. It has been directed that Article 12 requires the abolition of any criminal defence which relieves or mitigates liability on the basis of a mental disorder. In this article, it is determined that the partial defence of diminished responsibility is not compliant with the CRPD because it does not fully respect a person’s legal capacity and it provides a special defence to persons with a disability, holding them to a lesser standard of behaviour than others. As diminished responsibility was specifically introduced as a response to the mandatory life sentence of murder, this article recommends that the defence of diminished responsibility should be replaced with a provision which allows discretionary sentencing for murder where the court is satisfied that the accused had a psychosocial disability at the time of the offence which substantially diminished their ability to understand their actions or control their behaviour.