Chain of Custody Imperative Safeguarding Drug Evidence in Philippine Law

In drug cases, the prosecution's success often hinges on one crucial detail: the integrity of the seized item. The Supreme Court's 2009 decision in People v. Partoza (G.R. No. 182418) serves as a powerful reminder that police must strictly follow the chain of custody rule under Section 21 of Republic Act No. 9165. When they fail to do so, even a seemingly solid buy-bust operation can collapse, leading to an acquittal based on reasonable doubt.

The Case: A Buy-Bust Operation in San Mateo

On 2 November 2002, police officers in San Mateo, Rizal conducted a buy-bust operation against Edwin Partoza y Evora, who was suspected of selling shabu. A police officer acted as a poseur-buyer and purchased one plastic sachet of shabu for P100.00. After the exchange, the officer arrested Partoza and recovered another sachet from his hand. Both sachets tested positive for methamphetamine hydrochloride.

The Regional Trial Court convicted Partoza of illegal sale and illegal possession of dangerous drugs. The Court of Appeals affirmed the conviction. On appeal, the Supreme Court reversed the decision and acquitted Partoza.

The Issue: Did the Police Follow the Rules?

Partoza argued that the prosecution failed to observe the chain of custody requirement under Section 21 of R.A. No. 9165. He questioned the integrity of the evidence, pointing out that the seized items were not marked immediately at the scene.

The prosecution countered that Section 21 was not yet applicable at the time of the crime. The Office of the Solicitor-General also argued that the officer held on to the sachets from confiscation until marking at the police station.

The Ruling: Strict Compliance with Section 21

The Supreme Court ruled in favor of Partoza. The Court held that the prosecution failed to prove the identity of the corpus delicti—the body of the crime—beyond reasonable doubt.

Under Section 21(1) of R.A. No. 9165, the apprehending team must, immediately after seizure, physically inventory and photograph the seized drugs in the presence of:

• The accused or his representative or counsel;
• A representative from the media;
• A representative from the Department of Justice; and
• Any elected public official.

These witnesses must sign the inventory and receive copies.

In this case, the police officer admitted that he marked the sachets only at the police station, not at the scene. No inventory was made, no photographs were taken, and no required witnesses were present. The Court noted that while non-compliance is not automatically fatal if there is a justifiable ground, the prosecution offered no explanation for the lapses.

More importantly, the prosecution failed to show how the drugs were handled after they left the officer's custody. The officer mentioned a certain Inspector Manahan who signed the laboratory request but did not testify on the transfer of custody. The identity of the person who kept the drugs after examination and before trial was never established.

The Presumption of Regularity Does Not Apply

The courts below relied heavily on the presumption of regularity in the performance of official duties. The Supreme Court rejected this approach. Citing People v. Garcia, the Court explained that this presumption only arises when there are no details that raise doubt about the regularity of official conduct. When police officers fail to follow standard procedures, there is no occasion to apply the presumption.

Practical Takeaways

• Immediate marking is critical. Seized drugs should be marked at the scene of arrest, in the presence of the accused, not later at the police station.
• Document every transfer. The prosecution must account for the custody of the drugs from seizure, to the crime laboratory, to the court. Gaps in this chain can be fatal.
• Secure the required witnesses. The presence of media, DOJ, and elected public officials at the inventory is mandatory. Their absence must be justified with a credible explanation.
• The presumption of regularity is not a safety net. Police officers cannot rely on this presumption when they have demonstrably failed to follow the law.
• For the accused, procedural lapses matter. A conviction is not automatic even when a buy-bust operation appears successful. The integrity of the evidence is paramount.

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