Title page for ETD etd-08272012-173924

Document Type Master's Dissertation
Author Moller, Liezl
URN etd-08272012-173924
Document Title The constitutionality of the onus of proof in cases where mental illness is averred
Degree LLM
Department Public Law
Advisor Name Title
Prof P A Carstens Supervisor
  • Criminal Procedure Act 51 of 1977
  • mental illness
  • South African law
Date 2012-04-11
Availability unrestricted
This dissertation deals with the constitutionality of the onus of proof in cases where mental illness is averred.

Insanity refers to the legally defined state of mind and not to a specific psychological disorder. Mental illness is one of the factors recognised by South African law which negates criminal responsibility. The law recognises that persons suffering from insanity cannot be sanctioned in the same way as sane offenders.

The law applicable in South Africa today with regards to the insanity defence is contained in the provisions of the Criminal Procedure Act 51 of 1977, which replaced the MíNaghten rules and irresistible impulse test that appeared in South African Law nearly a century before.

Section 78(1) of the Criminal Procedure Act stipulates that in order to not be responsible for an alleged crime the accused must have committed an act which constitutes an offence and must at the time of said commission have suffered from a mental illness or mental defect which rendered him incapable of (a) appreciating the wrongfulness of his actions; or (b) acting in accordance with an appreciation of the wrongfulness of his actions.

Due to legislative amendments any party who raises mental illness as a defence is supposed to prove on a balance of probabilities that the accused was mentally ill at the time of the commission of the offence. This constitutes a departure from the normal rules of evidence which requires the state to prove the accusedís guilt beyond a reasonable doubt.

The test for insanity is therefore a mixed one in which expert testimony is vital. Psychologists as well as psychiatrists play an important role in assisting the court, by way of expert testimony, to determine the mental state of offenders. Lawyers and mental health professionals often donít see eye to eye as a result of the differences in interpretation and application of mental illness in the respective professions. The various difficulties faced by the defence, as a dependant of the professions, is explored.

A comparative study of the laws relating to the insanity defence in English Law and in the United States of America is conducted. These findings are contrasted to the current South African legal position. The selected jurisdictions share a common thread in that the insanity defence in these countries all originated from the MíNaghten rules and was subsequently modified by each.

In the English law system, a general insanity defence is non-existent today. The strict MíNaghten rules are still applied as the test for insanity and seldom evoked by accused persons.

In the United States of America the test for insanity differs from state to state but all have returned to the stricter English approach despite a number of different tests being developed and applied during the years since the defenceís existence.

The presumption of innocence, which means that the burden of establishing the elements of criminal liability lies with the prosecution and is a fundamental aspect of the South African criminal justice system. In all three of the legal systems the burden of proof has always been placed on the defence to prove its case on a balance of probabilities. Following the legislative amendments in South African law, in section 78 (1) (A) and (B), this position has now changed to he who alleges must prove.

Whether it constitutes unfair discrimination on the mentally ill accused to burden him with this higher onus than in normal defences, and whether it will survive constitutional scrutiny, concludes the study.

Copyright © 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.

Please cite as follows:

Moller, L 2011, The constitutionality of the onus of proof in cases where mental illness is averred , LLM dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-08272012-173924 / >


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