Reliability of Poseur Buyer Testimony in Drug Sale Convictions

The Supreme Court has long held that a conviction for illegal drug sale can rest on the testimony of a single prosecution witness, provided that witness is credible and the testimony is positive. In Lapuz v. People (G.R. No. 150050, June 17, 2004), the Court reaffirmed this principle and clarified the probative value of a police poseur buyer's account, even when the officer cannot recall the serial numbers of the marked money used in a buy-bust operation. The ruling offers practical guidance for both prosecutors and persons accused of drug offenses.

The Facts of the Case

On May 29, 1996, the Drug Enforcement Group of the Northern Police District Command in Valenzuela received information that a certain "Erning" was selling prohibited drugs. A buy-bust team was formed, and PO3 Cesar J. Pineda was assigned as the poseur buyer, carrying two P100 bills whose serial numbers were recorded in a police logbook.

Pineda approached the accused, Rufino Lapuz, and asked to buy P200 worth of "shabu." Lapuz handed over two plastic sachets of white crystalline substance taken from his pants pocket. When Lapuz realized his buyer was a police officer, he tried to flee but was apprehended. The substance was later confirmed to be methamphetamine hydrochloride, a regulated drug.

Lapuz was charged with violation of Section 15, Article III of Republic Act 6425, as amended by RA 7659 (the Dangerous Drugs Act of 1972). The trial court convicted him, and the Court of Appeals affirmed. Lapuz appealed to the Supreme Court.

The Issue

The central question was whether the bare testimony of the poseur buyer—who could not recall the serial numbers of the marked bills—was sufficient to establish the sale and support a conviction. Lapuz also raised issues about the non-presentation of the police logbook and whether he bore the burden of proving improper motives on the part of the arresting officers.

The Ruling

The Supreme Court denied the petition and affirmed Lapuz's conviction. The Court reiterated that a conviction may rest on the testimony of a single witness if that testimony is positive and credible. This is especially true when the witness is a police officer, who enjoys the presumption of regularity in the performance of official duties.

To sustain a conviction based on a single prosecution witness, the testimony must establish: (1) the identity of the buyer, seller, object, and consideration; and (2) the delivery of the thing sold and the payment therefor. What is material is proof that the transaction actually took place, coupled with the presentation in court of the seized substance as evidence.

On the Marked Money and the Logbook

The Court found that Pineda's failure to recall the serial numbers of the two P100 bills did not discredit him. Expecting a witness to recall such details from the witness stand is unreasonable, given that serial numbers consist of complex combinations of characters. The Court noted that honest inconsistencies on minor matters can actually strengthen a witness's credibility.

The marked money itself was identified in court by Pineda as the same bills he paid to the accused. The logbook, which recorded the serial numbers, would only have served as corroborative evidence. Its non-presentation did not create a gap in the prosecution's case, and the failure to produce it did not constitute willful suppression of evidence. The presumption of suppression does not apply to corroborative evidence.

On the Burden of Proof

Lapuz argued that the prosecution failed to prove the police officers were not improperly motivated. The Court clarified that the burden was on the accused to overcome the presumption of regularity in the performance of official duties. This can be done only through clear and convincing evidence showing either that the officers were not properly performing their duty or that they were inspired by improper motive. Lapuz presented no such evidence.

Practical Takeaways

• A single credible witness can sustain a drug sale conviction. The prosecution need not present multiple witnesses if the poseur buyer's testimony is positive, clear, and worthy of belief.
• Failure to recall serial numbers of marked money is not fatal. Courts recognize human memory limits, and the physical identification of the money in court may suffice.
• The marked money itself is not indispensable. What matters is proof that the sale actually took place and that the seized substance is presented in evidence.
• The accused bears the burden of attacking police credibility. Absent clear and convincing evidence of improper motive or irregular performance of duty, the presumption of regularity stands.
• Corroborative evidence need not always be presented. The non-presentation of corroborative documents, such as a police logbook, does not weaken the prosecution's case.

This article is general information and not legal advice. For your specific situation, consult a lawyer or ask ASG Legal AI.