FACTS:

The appellant, Tiburcio Abalos, was accused of the complex crime of direct assault with murder. The incident happened on March 20, 1983, during the barangay fiesta celebrations in Barangay Canlapwas, Catbalogan, Samar. Felipe Basal, a prosecution witness and a farmer residing in Barangay Pupua, Catbalogan, Samar, testified that appellant assaulted the victim, Pfc. Sofronio Labine. The incident occurred near the house of the appellant. According to Basal, appellant's father, Police Major Cecilio Abalos, was scolding his employees when appellant arrived. Appellant asked his father not to scold them, and this led to a heated argument between father and son. During the argument, a woman shouted for help, and Labine arrived at the scene and saluted Major Abalos. As Major Abalos pointed his carbine at Labine, appellant left and returned with a piece of wood. He then struck Labine from behind, causing him to collapse and later die from a severe skull fracture. Felipe Basal and his wife fled the scene in fear. Appellant admitted to striking Labine but claimed it was because he mistakenly thought his father was being attacked by an NPA member. He surrendered to the authorities when he found out the identity of his victim. The lower court rejected appellant's version of events and found him guilty of the crime charged. Appellant appealed the decision, alleging errors in the lower court's assessment of the evidence.

ISSUES:

1. Whether the trial court erred in crediting the testimony of the prosecution's sole witness and in disregarding the defense's claim of mistaken identity.

2. Whether treachery was correctly appreciated to qualify the killing to murder.

3. Whether the aggravating circumstances of evident premeditation and nocturnity, and the mitigating circumstance of voluntary surrender were duly considered.

4. Whether the imposition of the death penalty was appropriate.

RULING:

1. The Supreme Court affirmed the trial court's decision to credit the testimony of the prosecution's witness, dismissing the defense's claims of flawed credibility. It was held that the testimony was clear, positive, and there was no evidence of improper motive.

2. Treachery was found to be present as the accused attacked the victim from behind, ensuring the victim could not defend himself, which qualified the killing to murder.

3. The Supreme Court agreed with the lower court's findings that neither evident premeditation nor nocturnity was sufficiently proven. However, even though the appellant's voluntary surrender was recognized, it was deemed inconsequential given the nature of the complex crime charged.

4. Initially, the appropriate penalty would have been death due to the classification of the more serious crime being murder. Nonetheless, the penalty was necessarily reduced to reclusion perpetua, respecting the then-operative proscription against the imposition of the death penalty. The court also corrected the erroneous designation of "life imprisonment" to the proper term, reclusion perpetua.

PRINCIPLES:

1. The credibility of a lone eyewitness can suffice to sustain a conviction if the testimony is credible and positive.

2. The concept of treachery (alevosia) requires the employment of means of execution that give the person attacked no opportunity to defend himself or retaliate.

3. A complex crime occurs when a single act constitutes two or more grave or less grave felonies, or when an offense is a necessary means for committing another.

4. In cases involving complex crimes like direct assault with murder, the prescribed penalty is that for the graver offense to be imposed in its maximum period, regardless of mitigating circumstances.

5. The correct penalty term for serious offenses such as murder, when the death penalty is inapplicable, is reclusion perpetua, not "life imprisonment".

6. Veracity in testimony, recognition of aggravating and mitigating circumstances, and proper characterizations of penalties, are crucial in the just determination and adjudication of criminal cases.