CRIMINAL LAW — Defences — Insanity — Requirements for Establishing Defence
Ratio Decidendi
Per Adekeye, JSC, in Edoho v. State (2010) NLC-123-372-2007(SC) at p. 14, para. E – p. 15, para. A:
"In order to establish the defence of insanity, the defence must first show that the accused was at the relevant time suffering from either mental disease or from natural mental infirmity. Then it must be established that the mental infirmity as the case may be was such that at the relevant time the accused was as a result deprived of capacity to (a) understand what he was doing or (b) control his actions (c) know that he ought not to do the act or make the omission."
Explanation / Scope
This principle establishes the requirements for the defence of insanity: proof of mental disease or natural mental infirmity, and proof that this deprived the accused of the capacity to understand, control actions, or know the act was wrong. The principle applies where insanity is pleaded. It ensures that the defence is properly established. The principle reflects the legal test for insanity. It prevents misuse of the defence. The court must require proof of both elements. The principle provides guidance on establishing insanity.