Defenses Against Mens Rea

chapter 9 Defenses against Mens Rea

9.1 Introduction

Apart from the evidentiary burden, the prosecutor bears the onus to proof mens rea on part of the accused, there are several defenses at the disposal of the defense to refute the mens rea component. In criminal law, a theoretical distinction has been made between defenses by way of an excuse and defenses by way of a justification. This distinction, although less prominent in the defenses listed in the Rome Statute, is relevant as it pertains to different aspects of the accused’s mens rea. The Rome Statute lists, in article 31, “grounds for excluding criminal responsibility”, which are:

– A mental disease or defect; – Intoxication; – Self-defense or defense of others; and – Duress and necessity.1

The defense of mistake of fact or law and the defense of superior orders are covered by respectively article 32 and 33 ICCSt. The distinction between excuses and justifications also relates to the accused’s mental state. In defenses that are qualified as excuses, the defendant admits to have committed a criminal act, but claims that he cannot be held criminally responsible because he lacked criminal intent. It does not negate the wrongfulness of an action, but it sees at the culpability of the accused.2 Defenses being justifications, on the other hand, negate the wrongdoing of an action by transforming what would otherwise be an unlawful action into a lawful one.3 Excuses, such as duress, intoxication, mental disease or defect, superior orders, mistake of law and mistake of fact impede the free will of the defendant. Justifications, such as self-defense, defense of others and necessity, involve a choice of evils. According to one scholar, defenses of justification

1 Article 31(1)(a) to (d) ICCSt. 2 Jens Ohlin, “Part B Issues, Institutions and Personalities, E, Excuses and Justifications,” in The Oxford Companion to International Criminal Justice, ed. Antonio Cassese (Oxford: Oxford University Press, 2009), 319. 3 Ibid., 318.

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“pertain specifically to mens rea, because, unlike most excuse defenses, the defendant has made a meaningful choice.”4 Yet, Dinstein identified the defense of duress, mistake of law or fact, and mental disease, as the most prominent defenses pertaining to the absence of mens rea.5 In short, excuses pertain to the blameworthiness of the actor, while justifications pertain to the (in)cor- rectness of the act.6 This chapter will go into each of the defenses listed in the Rome Statute, while referring to the application of these defenses in the past, and discuss if and how they relate to the accused’s mens rea or lack thereof.

9.2 Mental Disease or Defect

9.2.1 General Analysis A defendant cannot incur criminal responsibility under the Rome Statute if his actions were the result of a mental disease or defect, that affected his “capacity to appreciate the unlawfulness or nature of his or her conduct, or capacity to control his or her conduct to conform to the requirements of law”.7 If the defendant – at the time of the commission of the crimes – lacked the capabil- ity to engage in moral reasoning or to control his behavior, he lacked the cul- pable mental state necessary to reach a conviction.8 The defense, sometimes referred to as the insanity defense, revolves around the question whether the accused possessed the requisite mens rea at the time of the alleged crimes.9 If the requisite mens rea was lacking due to a mental disease or defect, a decisive element of the crime cannot be fulfilled, which should necessarily lead to an

4 Noah Weisbord, “The Mens Rea of the Crime of Aggression,” Washington University Global Studies Law Review 12, 3 (2013): 500. 5 Yoram Dinstein, “International Criminal Courts and Tribunals, Defences,” in Max Planck En- cyclopedia of Public International Law (Oxford University Press: 2009), accessed 21 June 2016, http://opil.ouplaw.com/. 6 Kai Ambos, “Grounds Excluding Responsibility (‘Defences’),” in Treatise on International Criminal Law: Volume 1: Foundations and General Part, ed. Kai Ambos (Oxford: Oxford Uni- versity Press, 2013), 306. 7 Article 31(1)(a) ICCSt. 8 Jens Ohlin, “Issues, Institutions and Personalities, M, Mental Disease,” in The Oxford Compan- ion to International Criminal Justice, ed. Antonio Cassese (Oxford: Oxford University Press, 2009), 415; see also Shane Darcy, “Defences to International Crimes,” in Routledge Handbook of International Criminal Law, ed. William A. Schabas and Nadia Bernaz (New York: Rout- ledge, 2011), 231–245. 9 John Tobin, “The psychiatric defence and international criminal law,” Medicine, conflict and Survival 23, 2 (2007): 113.