Chain of Custody in Drug Cases: Why Gaps Lead to Acquittal Under RA 9165

In drug prosecutions, the seized substance is the very heart of the case. The prosecution must prove not only that the accused sold or possessed illegal drugs, but also that the drugs presented in court are exactly the same items seized from the accused. When the chain of custody is broken, the integrity of the evidence collapses, and conviction becomes impossible.

In People v. Bermejo (G.R. No. 199813, June 26, 2019), the Supreme Court underscored this principle by acquitting Allan Bermejo, who had been sentenced to life imprisonment for selling shabu. The Court found that the prosecution failed to establish an unbroken chain of custody, leaving reasonable doubt on the identity of the seized drugs.

The Case: A Buy-Bust Operation Under Scrutiny

Bermejo was arrested in February 2003 during a buy-bust operation in Puerto Princesa City. A civilian asset acted as poseur-buyer and allegedly purchased two sachets of shabu from Bermejo using four marked P100 bills. The police arrested Bermejo, marked the sachets at the police station, and later submitted them for laboratory examination. The trial court convicted Bermejo, and the Court of Appeals affirmed. On appeal, the Supreme Court reversed the conviction.

The Four Links of the Chain of Custody

The Court reiterated that the chain of custody has four links that the prosecution must prove:

1. Seizure and marking — the apprehending officer marks the seized drugs, ideally at the place of arrest and in the presence of the accused;
2. Turnover to the investigating officer — the seized item is transferred to the investigator;
3. Turnover to the forensic chemist — the item is submitted for laboratory examination; and
4. Turnover to the court — the chemist or evidence custodian presents the item in court.

Each person who handled the item must testify on how it was received, what was done to it, and how it was passed on. This ensures that the evidence was not switched, planted, or contaminated.

Gaps That Destroyed the Prosecution's Case

In Bermejo, the Court identified several fatal gaps:

Marking was delayed. The sachets were marked only upon arrival at the police station, not at the scene of arrest. The officers offered no justification for the delay, and there was no proof that the marking was done in Bermejo's presence. Marking at the earliest opportunity prevents switching or planting of evidence.

Witnesses signed the inventory later. The inventory receipt was signed by representatives from the DOJ, media, and barangay, but they signed the day after the arrest—without Bermejo present. The prosecution did not explain this deviation.

No photographs taken. The police failed to photograph the seized items and offered no explanation for the omission.

The laboratory link was unclear. The request for laboratory examination was received by a certain "PO2 Buyuccammo," not the forensic chemist who tested the drugs. The prosecution did not explain how the specimen was handled while in that person's custody. Worse, the specimen was submitted to a crime laboratory in Laguna but was actually examined in Calapan City, Oriental Mindoro—a transfer never explained.

Inconsistent weights. The request stated the sachets weighed "more or less 0.2 gram," but the chemistry report showed each sachet weighed 0.3 gram, for a total of 0.6 gram. This discrepancy was never clarified.

Mixing with other cases. The officer testified that he brought the specimen along with drugs from other suspects to the laboratory. The possibility of mix-up was real, and the prosecution failed to rule it out.

The Saving Proviso Does Not Apply Automatically

Section 21 of RA 9165, as amended, allows noncompliance with the inventory and photograph requirements if there are justifiable grounds and the integrity of the evidence is preserved. But the Court stressed that the prosecution must first acknowledge and explain the lapses. In Bermejo, the prosecution neither recognized nor explained any deviation, so the saving proviso could not save the case.

Practical Takeaways

• Mark drugs immediately. The safest practice is to mark seized items at the place of arrest, in the presence of the accused, and to document the moment.
• Photograph and inventory properly. Take photographs and conduct the inventory with the required witnesses—an elected official and a media or DOJ representative—and have everyone sign in the accused's presence.
• Document every transfer. Every handler of the evidence must be identified, and the prosecution must be ready to present each one in court.
• Explain any deviation. If the prescribed procedure cannot be followed, the apprehending team must record the justifiable reason and show that the evidence was nonetheless preserved.
• For defense lawyers: Scrutinize the chain of custody for gaps—delayed marking, unexplained transfers, missing witnesses, and inconsistent weights are fertile ground for reasonable doubt.

The Bermejo ruling is a reminder that in drug cases, procedural compliance is not mere formality. It is the safeguard that keeps the evidence trustworthy—and the accused's liberty secure.

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