The admission by Virgilio Obzunar that he was the one who administered the fatal stab wound albeit in self-defense shifts the burden of proof upon him to show that the killing was justified and that he incurred to criminal liability therefor. As is the rule in such cases, it is incumbent upon the accused to establish that all the elements necessary to a claim of self-defense were present, and he can rely only "on the strength of his own evidence and not on the weakness of the prosecution's evidence, for, even if the latter were weak, it could not be disbelieved after his open admission of responsibility for the killing." [G.R. No. 92153. December 16, 1996]
