Broken Chains: Safeguarding Drug Evidence and Protecting Rights in Philippine Law

In drug cases, the prosecution must prove not only that the accused sold or possessed illegal drugs, but also that the very items presented in court are the same ones seized from the accused. This is called the chain of custody rule. In People v. Coreche (G.R. No. 182528, August 14, 2009), the Supreme Court acquitted a woman convicted of selling and possessing shabu because the police failed to establish an unbroken chain of custody over the seized drugs. The ruling is a reminder that the presumption of innocence prevails over the presumption of regularity in police work.

The Facts of the Case

In the early morning of September 10, 2003, police officers in San Mateo, Rizal received a tip from an informant that Marian Coreche was selling shabu. They conducted a buy-bust operation. A police officer and the informant posed as buyers and purchased a plastic sachet of shabu from Coreche using marked money. After the sale, the officers arrested Coreche and recovered the marked bills and two more plastic sachets from her. Her sister, Emily, was also arrested with two sachets.

The police brought the suspects to the station, marked the sachets, and sent them to the crime laboratory. The contents tested positive for methamphetamine hydrochloride. Coreche was charged with sale and possession of dangerous drugs under Sections 5 and 11 of Republic Act No. 9165 (the Comprehensive Dangerous Drugs Act of 2002). The trial court convicted her, and the Court of Appeals affirmed.

The Issue

The sole issue was whether the prosecution proved Coreche's guilt beyond reasonable doubt for the sale and possession of methamphetamine hydrochloride.

The Ruling

The Supreme Court reversed the conviction and acquitted Coreche on the ground of reasonable doubt. The Court held that the prosecution failed to prove the corpus delicti—the body of the crime—because of substantial gaps in the chain of custody of the seized drugs.

First Gap: Marking at the Police Station, Not at the Arrest Site

Marking the seized drugs immediately after seizure is the starting point of the chain of custody. It separates the evidence from all other similar items and prevents switching, planting, or contamination. While the plastic sachets in this case were marked "HVA, HVA-1, and HVA-2," the record did not show when and where the marking was done. One police officer admitted that he marked the sachets he seized from Emily at the police station, not at the arrest site. This created a strong inference that the other officer also marked the sachets at the station, not immediately upon confiscation.

The Court cited People v. Zarraga (G.R. No. 162064, March 14, 2006), where conflicting testimonies on when and where the drugs were marked created reasonable doubt. Marking at the station, instead of at the scene, violates the standard procedure and casts doubt on the authenticity of the evidence.

Second Gap: Unclear Post-Examination Custody

The prosecution also failed to prove who had custody of the drugs after the laboratory examination. The parties stipulated that the forensic chemist placed the specimens in a plastic bag with markings and initialed it after testing. However, the stipulation did not state whether the specimens remained in the chemist's safekeeping or were transferred elsewhere before trial. This equivocal evidence left a second gap in the chain.

Presumption of Innocence Prevails

The lower courts relied on the presumption that police officers regularly performed their official duties. But the Court emphasized that this presumption is not conclusive. It is rebutted by contrary proof and is inferior to the constitutional presumption of innocence. Because the prosecution failed to prove the identity and integrity of the seized drugs, the conviction could not stand.

Practical Takeaways

• Mark immediately. Police officers must mark seized drugs at the arrest site, in the presence of the accused, not later at the station.
• Document every transfer. The prosecution must account for the custody of the drugs at every stage—from seizure, to the laboratory, to the court.
• Stipulations must be precise. Stipulations of fact must clearly state who held the evidence after examination; vague stipulations create gaps.
• Presumption of regularity is not enough. The prosecution cannot rely solely on the presumption of regularity; it must present actual proof of an unbroken chain.
• For the accused, gaps mean acquittal. Substantial gaps in the chain of custody raise reasonable doubt and warrant acquittal, even if the drugs test positive.

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