Accuse-appellant must thus prove that he was completely deprived of reason when he killed his father in order to be exempt for parricide.
There is nothing either in the report of Dr. Gerona or his testimony which indubitably show that accused-appellant was completely without reason when he killed his father because the latter wanted him to leave the house.
The defense of insanity is in the nature of confession and avoidance and, like the justifying circumstance of self- defense, the burden is on the defense to prove beyond reasonable doubt that the accused was insane immediately before the commission of the crime or at the very moment of its execution.
Although schizophrenia is not exempting if it does not completely deprive the offender of the consciousness of his acts, it may nevertheless be considered mitigating under Art 13 (9) if it diminishes the exercise of his will power. (PEOPLE vs. BANEZ, G.R. No. 125849, January 20, 1999)