Burden of guilt: Guide to an insanity defence

If ‘insanity’ is a purely legal concept these days, what is Uganda’s landmark case?
Inarguably, the most referenced insanity plea case is that of Ivan Mwesigwa, who in May of 2011, fatally wounded his brother with a hand hoe after a dispute. Evidence adduced by Mwesigwa’s mother—Gertrude Wakabi—who herself came within a whisker of being lynched, “proved beyond reasonable doubt” that he killed his brother. 

Ms Wakabi also confirmed that her son, who stood accused of killing with malice aforethought, was committed to Butabika National Referral Mental Hospital in 2008 with what was later diagnosed as bipolar affective disorder. This was after the accused raised the defence of insanity. 

What sort of defence does it offer?
Unlike provocation, Uganda’s criminal codes establish insanity as a complete defence. Provocation typically merits a partial defence, with the burden of proof shouldered solely by the accuser (plaintiff). Insanity is an entirely different animal, with the law putting the burden of proof on the accused (defendant) rather than the accuser (plaintiff). It, therefore creates what can be described as a burden of guilt.

This essentially means that the burden of proof shifts to the accused (defendant). The threshold of evidence is, therefore, above the balance of probabilities—as indeed in most civil cases—but not beyond reasonable doubt. Put simply, something proven on a balance of probabilities is more likely than not to have occurred. This puts it above that notoriously difficult 50 percent threshold. 

It should also be noted that—unlike a partial defence—a complete defence means if the accused can successfully prove insanity at the time of committing an offence, they are exonerated. 

What other barriers must the accused hurdle?
Uganda’s criminal codes proffer a test of incapacity that—broadly speaking—denies the insanity plea defence to a person generally believed to have possessed the power of self-control over their conduct. The test considers the material facts of an individual who carried out the act. While the accused may have a history of mental problems/challenges, as indeed was the case with Mwesigwa, the test in question examines the conduct of the accused at the time they carried out an act.

Do the scientific understandings of mental illness vis-à-vis criminal behaviour count for much? 
Ultimately, granular details such as ascertaining whether the cognitive capacity is partial rather than total or the interpretation of the “nature and quality” of conduct of the accused come into sharp focus. In Mwesigwa’s case, High Court Justice Godfrey Namundi “came to the conclusion that the accused is mentally alert and capable of appreciating his actions and their consequences.” This was after “observing the demeanour of the accused throughout the trial and during his defence.”

So Mwesigwa failed to bear the burden of persuading the fact-finder of the truth of his claim?
In a word, yes. For the sake of clarity, the judge made clear that “for one to benefit from the defence of insanity, there must be evidence that the accused was at the time of committing the offence incapable of appreciating or understanding what he was doing.”

Justice Namundi added: “The medical evidence produced shows that the accused has ever had treatment for mental disorders. No evidence was led to show that the accused had occasional lapses where he became either aggressive or committed similar offences or acts. There is no evidence that the accused is still undergoing treatment for his mental issues or was so doing at the time he committed the offence.”

What else constitutes the moral basis of the insanity defence?
Mr Stanley Yeo’s peer reviewed article titled ‘The Insanity Defence in the Criminal Laws of the Commonwealth of Nations’ warns of the danger of using words that impute finality. This is especially so “when describing the accused’s perception of the nature and quality of his or her conduct.” In Mwesigwa’s case, Justice Namundi hastened to dismiss the assessors’ opinion that the accused’s arrest in his mother’s bedroom was indicative of an aura of innocence.

“…there is no other evidence to show that at the material time, the accused was incapable of appreciating the consequences of his activities,” Justice Namundi said of Mwesigwa hiding in his mother’s bedroom a day after killing his brother.

Background
In January, statistics from the Ministry of Health and the Uganda Counselling Association showed that the estimated incidence of mental illnesses was massive, with 35 percent of Ugandans suffering from mental illness, and 15 percent needed treatment. It was likely that the incidence of mental illness and the need for treatment was getting higher.

According to the data, only 20 percent of adolescents and children with mental illness were receiving the therapy they needed.