"It is essential, from social and public stand point, to closely examine a defence of insanity. It is necessary to recognize that there could be serious evil consequences if men should act on self-induced intoxication and seek to avoid to take the legal consequences of their act upon a claim that they are insane. This need to protect society is recognized even in an assault case. (See D.P.P. v. Mojewski (1975) 3 W.L.R. 404 Per Lawton, L.J. and the judgment of Lord Elwyn-Jones, L.C., on appeal to the House of Lords in the case in (1976) 2 All E.R at P.145 let alone in cases involving the taking of lives." at page 29 of the report. 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. And the surest way of establishing insanity is by medical evidence or by compelling evidence of eyewitnesses, particularly of the relatives of the appellant, relating to his general conduct and behavior prior to, during and after the incident in question. Anthony Ejinma v. The State (1991) 7 SCNJ (pt. 1) 318 at 328. In M.A. Sanusi v. The State (1984) 10 SC 166 at 177 - 178, his Lordship, Anagiolu, JSC., emphatically stated what is expected in pieces of evidence aimed at establishing and proving insanity, as: "Positive act of the accused, before and after the deed complained of; evidence by a doctor who examined and watched the accused over a period of time as to his mental state; evidence of relatives who know the accused person intimately relating to his behavior and the change which had come upon him; the medical history of the family which could indicate hereditary mental affliction or abnormality, and such other facts and circumstances which will help the trial judge come to the conclusion that the burden of insanity placed on the accused, has been simply discharged." The salient facts required in proving insanity were clearly projected and crystalised by the apex court again, in Onyejekwe v. The State (1988) 1 NWLR (pt.72) 565 at 579 - per my Lord, Oputa, JSC., to include: "(1) Evidence as to the past history of the accused; (2) Evidence as to his conduct immediately preceding the killing of the deceased; (3) Evidence from prison warders who had custody of the accused and looked after him during his trial; (4) Evidence of medical officers and/or Psychiatrics who examined the accused;