Navigating the Chain: Ensuring Drug Evidence Integrity in Philippine Law

In drug cases, the seized substance itself is the very heart of the prosecution's case. If the integrity of that evidence is compromised, the accused may be acquitted even if police officers testify credibly about the arrest. The Supreme Court's 2019 decision in People v. Maylon y Alvero clarifies a practical question that often arises in buy-bust operations: must marking and inventory always happen at the exact place of arrest, or can the police validly do these steps at the nearest station?

The Court ruled that moving to a nearby police station is acceptable when circumstances — such as a hostile crowd — make on-site procedure unsafe, provided the required witnesses are present and the chain of custody remains unbroken.

The Facts of the Case

On August 10, 2014, operatives of the Station Anti-Illegal Drugs Special Operation Task Group of Marikina City conducted a buy-bust operation against Jonathan Maylon and Arnel Estrada. Maylon allegedly sold one plastic sachet of shabu to poseur-buyer PO3 Junar Olveda. Police also recovered seven sachets from Maylon and one from Estrada.

The team immediately marked the seized items at the place of arrest. However, because relatives of the accused began causing a commotion, the officers moved to the nearest police station to conduct the inventory and photography. The inventory was done in the presence of two elected public officials — a barangay kagawad and a councilor — and a media representative. The seized items were then delivered to the crime laboratory, where tests confirmed they contained methamphetamine hydrochloride.

Maylon and Estrada were convicted by the Regional Trial Court and the Court of Appeals. They appealed to the Supreme Court, arguing that the chain of custody was broken because the inventory was not done at the place of arrest.

The Issue

The central question was whether the buy-bust team's decision to conduct the inventory at the police station, rather than at the arrest site, violated the chain of custody rule under Section 21, Article II of Republic Act No. 9165 (the Comprehensive Dangerous Drugs Act of 2002), thereby compromising the integrity of the seized drugs.

The Ruling: Sufficient Compliance

The Supreme Court dismissed the appeal and affirmed the convictions. The Court held that the prosecution had sufficiently complied with the chain of custody rule, and the integrity and evidentiary value of the seized drugs were preserved.

The Court reiterated that in drug cases, the identity of the dangerous drug must be established with moral certainty, because the drug itself is the corpus delicti of the crime. The prosecution must account for each link of the chain of custody — from seizure to presentation in court.

Significantly, the Court clarified that marking upon immediate confiscation "contemplates even marking at the nearest police station or office of the apprehending team." Thus, the failure to mark at the exact place of arrest neither renders the items inadmissible nor impairs the integrity of the drugs.

In this case, the move to the police station was justified. PO3 Olveda testified that the team decided to continue the inventory at the nearest precinct "to avoid any commotion" because relatives of the accused appeared ready to attack them.

The Court also noted that the buy-bust team had already secured the presence of an elected public official and a media representative even before the operation began — a practice that confirms compliance with the amended witness requirement under RA 10640, which amended RA 9165. The witnesses were waiting nearby while the operation was conducted.

The Witness Requirement Under RA 9165

The Court explained the witness requirement as it evolved. Before RA 10640 amended RA 9165, the law required the presence of a representative from the media, the Department of Justice, and any elected public official. After the amendment, the requirement became an elected public official and a representative of the National Prosecution Service or the media.

The presence of these witnesses serves a critical purpose: to ensure the establishment of the chain of custody and to remove any suspicion of switching, planting, or contamination of evidence.

Practical Takeaways

• Marking may be done at the nearest police station. The Supreme Court recognizes that marking at the nearest station or office of the apprehending team is sufficient compliance with the chain of custody rule, especially when on-site marking is impractical or unsafe.
• Safety concerns can justify relocation. A hostile crowd or commotion at the arrest site is a valid reason for police to move to a safer location to conduct the inventory, as long as the move is reasonable and properly explained.
• Secure witnesses before the operation. The best practice, as highlighted in this case, is to have the required witnesses already on standby before the buy-bust operation begins. This strengthens the prosecution's case and avoids questions about witness availability.
• Document every link in the chain. From marking to inventory to laboratory examination, each step must be accounted for. The prosecution must be able to show an unbroken chain of custody to establish the identity and integrity of the seized drugs.
• The drug is the corpus delicti. If the prosecution fails to prove the integrity of the seized substance, the evidence becomes insufficient to prove guilt beyond reasonable doubt, warranting acquittal.

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