G.R. No. L-11000; March 14, 1916
THE UNITED STATES, plaintiff-appellee, vs. VALERIO MENDIETA, defendant-appellant.

FACTS:
On or about February 22, 1914, in the municipality of Cauayan, Isabela, a quarrel arose over a cockfight bet between the accused, Valerio Mendieta, and one Hilario Lauigan at a cockpit in Barrio Barringin. The deceased, Pedro Acierto, was not involved in this quarrel. After the incident, as Pedro Acierto and his companions were leaving the cockpit, Valerio Mendieta rushed up behind Acierto and stabbed him in the back with a lance. The wound penetrated Acierto’s intestines, causing his death on March 17, 1914. Mendieta was charged with the crime of assassination. The Court of First Instance found him guilty, qualifying the killing with treachery and considering the mitigating circumstance of vindication of a prior offense by Hilario Lauigan, sentencing him to cadena temporal. The defendant appealed, arguing the evidence was insufficient to prove his guilt beyond reasonable doubt and claiming self-defense. He also contended he had intended to attack Lauigan, not Acierto.

ISSUE:
Whether the evidence is sufficient to prove beyond reasonable doubt that Valerio Mendieta is guilty of the crime of assassination with the qualifying circumstance of treachery.

RULING:
Yes. The Supreme Court affirmed the conviction but modified the penalty. The evidence established that Mendieta attacked Pedro Acierto from behind without any provocation, while Acierto was unaware and unable to defend himself, constituting the qualifying circumstance of treachery (alevosía). The claim of self-defense was unsupported by the record, as Acierto offered no offense or resistance. The defense that Mendieta mistakenly killed Acierto instead of his intended target, Hilario Lauigan, does not relieve him of criminal responsibility; mistake in identity is not a mitigating circumstance when the act is willful and malicious. The Court rejected the lower court’s finding of the mitigating circumstance of vindication, as the deceased was not the offender. Consequently, with treachery as the sole qualifying circumstance and no mitigating circumstances, the proper penalty is cadena perpetua. The decision was modified to impose the penalty of cadena perpetua, with the accessory penalties, an indemnity of P1,000 to the heirs of the deceased, and costs.