G.R. No. 137000 - Valles vs. Commission on Elections

On December 3, 1964, in Nueva Era, Ilocos Norte, Aurelio Balisacan stabbed Leonicio Bulaoat, causing wounds that led to the latter’s death.
On February 1, 1965, the Court of First Instance of Ilocos Norte charged Balisacan with homicide and, upon arraignment, he pleaded guilty with assistance of counsel.

At de oficio counsel’s petition, the court allowed Balisacan to present evidence solely to establish mitigating circumstances.
Balisacan testified he acted in self-defense—claiming the victim was strangling him—and that he voluntarily surrendered to police authorities.

On March 6, 1965, relying on the accused’s testimony, the court a quo acquitted Balisacan.
The prosecution appealed to the Court of Appeals (brief filed September 9, 1965). No appellee’s brief was filed.
On July 14, 1966, the Court of Appeals certified the case to the Supreme Court as one involving questions purely of law (Sec. 17, R.A. 296), and it was docketed on August 5, 1966.

Whether the trial court erred in acquitting the accused despite his plea of guilty at arraignment.
Whether the prosecution’s appeal places the accused in double jeopardy, barring the appeal under Section 2, Rule 122 of the Rules of Court.