Reasonable Doubt Prevails: Chain of Custody Breach in Drug Cases

The Supreme Court’s acquittal of Aiza Sampa y Omar in People v. Tayan is a powerful reminder that in drug cases, the prosecution’s case stands or falls on the integrity of the seized drugs. Even where a buy-bust operation appears successful, serious procedural lapses in the chain of custody can create reasonable doubt and warrant acquittal. This ruling, decided on July 8, 2019 (G.R. No. 242160), reaffirms the strict safeguards under Republic Act No. 9165 and its Implementing Rules and Regulations (IRR).

The Buy-Bust Operation and the Conviction Below

On February 24, 2014, PDEA agents conducted a buy-bust operation in Quezon City against Jan Jan Tayan and Aiza Sampa. A poseur-buyer purchased a plastic sachet containing 50.6374 grams of methamphetamine hydrochloride (shabu) from Tayan, with Sampa allegedly handing the drugs to him. The accused were arrested and charged with illegal sale of dangerous drugs under Section 5, Article II of R.A. No. 9165.

The Regional Trial Court convicted both accused, and the Court of Appeals affirmed. The prosecution argued that the failure to mark, inventory, and photograph the drugs at the place of arrest was justified by a commotion and that there was substantial compliance with the chain of custody rule. Sampa appealed to the Supreme Court.

The Issue: Did the Breach of Chain of Custody Create Reasonable Doubt?

The central issue was whether the PDEA agents’ deviation from Section 21 of the IRR of R.A. No. 9165 — specifically the failure to conduct marking, inventory, and photographing immediately at the place of seizure and in the presence of required witnesses — compromised the integrity of the seized drugs.

The Ruling: Acquittal for Failure to Prove Guilt Beyond Reasonable Doubt

The Supreme Court acquitted Sampa. The Court held that the prosecution failed to prove her guilt beyond reasonable doubt because the chain of custody was broken at its very inception.

Marking, Inventory, and Photographing Done Too Late and in the Wrong Place

The Court noted that the seized sachet was marked inside the service vehicle, not at the place of arrest. The inventory and photographing were done only upon arrival at the PDEA office in Camp Vicente Lim, Canlubang, Laguna — hours later and far from the arrest site in Fairview, Quezon City.

The prosecution invoked the existence of a commotion to justify the delay. The Court rejected this excuse, noting that the prosecution never provided details of the commotion or showed that it genuinely prevented compliance. The Court emphasized that while the IRR allows the procedure to be done at the nearest police station or office when immediate compliance is impracticable, the prosecution must prove the justifiable ground. A bare allegation of commotion, unsupported by evidence, does not suffice.

The Missing Three-Witness Rule

More critically, the apprehending team failed to secure the presence of the three insulating witnesses required by Section 21: a representative from the media, a representative from the Department of Justice (DOJ), and an elected public official.

The testimony of the poseur-buyer revealed that the team did not even attempt to contact a DOJ representative, reasoning that they are "usually not available." The only witness present — a media representative — merely signed the certificate of inventory and did not actually observe the inventory.

The Court reiterated that the presence of these witnesses is mandatory, not a mere formality. Their presence at the time of seizure and inventory protects against the evils of planting, switching, or contamination of evidence. Calling them in only after the operation has finished does not achieve the law’s purpose.

The Saving Clause Did Not Apply

The IRR’s saving clause allows non-compliance if there are justifiable grounds and the integrity and evidentiary value of the seized items are properly preserved. Here, the prosecution failed on both counts. It did not explain the lapses, and the absence of witnesses at the very start of the chain created serious doubt about whether the item seized was the same item examined in the laboratory.

Practical Takeaways

• Chain of custody is the heart of a drug case. The prosecution must show, with moral certainty, that the drugs seized are the same drugs examined in court. Any gap creates reasonable doubt.
• Mark, inventory, and photograph immediately. These steps must be done at the place of arrest or as soon as practicable. If not feasible, the apprehending team must proceed to the nearest police station or office — and must prove why the delay was justified.
• The three witnesses are not optional. A media representative, a DOJ representative, and an elected public official must be present during the seizure and inventory. Their absence, without a credible explanation, can be fatal to the prosecution.
• A "commotion" is not a magic word. Police officers cannot simply invoke a commotion to excuse non-compliance. The prosecution must present evidence of the commotion and show that it genuinely prevented compliance.
• For the defense, scrutinize the chain. In drug cases, defense counsel should focus on the procedural lapses in the chain of custody — the timing of the marking, the location of the inventory, and the presence of the required witnesses — as these are often the strongest grounds for acquittal.

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