RATIO DECIDENDI 1. EVIDENCE - BURDEN OF PROOF: On whom lies the onus of establishing the defence of drunkness which amounts to insanity and unsoundness of mind "The law is settled and beyond dispute that the onus of establishing the defence of drunkenness which amounts to insanity and unsoundness of mind, not to know what he did, rests squarely on the accused person. The burden is discharged on a preponderance of evidence led by and for the accused person. John Imo v. The State (1991) 9 NWLR (pt. 213) 13; (1991) 11 SCNJ 137 at 159 - 160. Generally, the law presumes that every human being is sane, until the contrary is proved. Section 27 of the Criminal Code." Per YAKUBU,J.C.A. (P.22,paras.C-F) (...read in context) 2. EVIDENCE - COMPETENT WITNESS: Whether a child is deemed a competent witness in law and under what circumstance will a child's sworn testimony not be needed in criminal trials "It is no doubt the settled position of the law that a child is a competent witness unless the court considers the child in question to be prevented from understanding the questions put to him by reason of tender years (i.e. his age). See Section 154 of the Evidence Act, Cap. 112 LFN, 1990. With specific reference to criminal proceedings the position of the law is that a child need not give sworn testimony if the child in the opinion of the court does not understand the nature of an oath but possesses sufficient intelligence to justify the receipt of his evidence and understands the duty of speaking the truth. See Section 182(1) and (2) of the Evidence Act (supra). The Supreme Court interpreted the provisions of Sections 154 and 182(1) and (2) of the Evidence Act (supra) in the case of OKON v. STATE (1988) 19 NSCC 156. In DAGAYYA v. THE STATE (2006) All FWLR (Pt.308) 1212 at pages 1232 - 1233 the Supreme Court per Tobi, JSC reiterated or echoed the position in Okon's case thus:- "As correctly pointed out by learned counsel for the respondent this court dealt with the matter in 1988 in the case of Okon v. State (supra) ........This court held that: (1) Once a witness is a child, by the combined effect of Sections 154 and 182(1) and (2) of the Evidence Act, the first duty of the court is to determine first of all whether the child is sufficiently intelligent to understand the questions he may be asked in the course of his testimony and to be able to answer rationally. This is tested by the court putting on (sic) him preliminary questions which may have nothing to do with the matter before the court. (2) If, as a result of these preliminary questions, the court comes to the conclusion that the child is unable to understand the questions or answer them intelligently, then the child is not a competent witness within the meaning of Section