A descendant is not incompetent or disqualified to testify against an ascendant; filial privilege can be invoked or waived like other privileges
Facts: Appellant Artemio was charged with the the crime of rape committed against his 16-year child. One of the witnesses of the prosecution was Elven, the 8-year-old son of Artemio with his second common-law wife. The trial court convicted Artemio. On appeal, he attacks the competency and credibility of Elven as a witness. He argues that Elven, as his son, should have been disqualified as a witness against him under Section 20(c), Rule 130 of the Rules of Court.
Held: The competency of Elven to testify is not affected by Section 25, Rule 130 of the Rules of Court, otherwise known as the rule on “filial privilege.” This rule is not strictly a rule on disqualification because a descendant is not incompetent or disqualified to testify against an ascendant. The rule refers to a privilege not to testify, which can be invoked or waived like other privileges. As correctly observed by the lower court, Elven was not compelled to testify against his father; he chose to waive that filial privilege when he voluntarily testified against Artemio. Elven declared that he was testifying as a witness against his father of his own accord and only “to tell the truth.” [People of the Philippines vs Artemio Invencion y Soriano, G.R. No. 142930, March 28, 2003]