Chain of Custody in Drug Cases: Why Unmarked Evidence Means Acquittal

In a buy-bust operation, the prosecution must prove not only that the accused sold illegal drugs, but also that the drugs presented in court are the very same items seized from the accused. This requirement, known as the chain of custody rule, is the backbone of drug prosecutions under Republic Act No. 9165, the Comprehensive Dangerous Drugs Act of 2002.

In People v. Butial (G.R. No. 192785, February 4, 2015), the Supreme Court reversed a conviction for illegal sale of shabu because the police failed to mark the seized sachets immediately after seizure. The case is a clear reminder that procedural lapses in handling evidence can lead to an acquittal, no matter how strong the prosecution's story may seem.

The Facts of the Case

On October 21, 2002, police officers in Tabaco City conducted a buy-bust operation against Jomer Butial, who was suspected of selling shabu. A police asset acted as poseur-buyer and purchased two plastic sachets of shabu from Butial for P400 in marked money. After the transaction, the asset handed the sachets to PO2 Martirez, who arrested Butial.

At the police station, the officers recovered one of the marked P100 bills from Butial's pocket. They also searched his backpack and found more sachets containing white crystalline substance. Two days later, five sachets were submitted to the crime laboratory, all testing positive for shabu.

Butial was charged with violating Section 5, Article II of RA 9165. The trial court convicted him and sentenced him to life imprisonment and a fine of P500,000. The Court of Appeals affirmed. On appeal, Butial questioned, among others, the integrity of the seized evidence.

The Issue: Was the Chain of Custody Broken?

The central issue was whether the prosecution had established that the shabu presented in court was the same shabu seized from Butial. The Court found that it had not.

The chain of custody requirement ensures that doubts concerning the identity of the evidence are removed. The first link in this chain is the marking of the seized items immediately after seizure. Marking separates the evidence from all other similar items and prevents switching, planting, or contamination.

The Court's Ruling: Acquittal

The Supreme Court granted the appeal and acquitted Butial. The prosecution failed to prove the identity and integrity of the corpus delicti—the body of the crime, which in drug cases is the illegal drug itself.

The Court pointed to several fatal gaps:

No markings on the buy-bust sachets. PO2 Martirez admitted that he did not mark the two sachets handed to him by the poseur-buyer. He claimed the police investigator may have initialed them, but he could not remember who did. The investigator, SPO1 Desuasido, never testified that he marked or even received the sachets.

Confusion over other markings. SPO4 Bonavente testified that he put his initials on some sachets, but it was unclear whether these were the buy-bust sachets or the ones later recovered from the ground and the backpack. When shown the evidence in court, he could not identify some of the markings.

Mismatched weights. The two sachets subject of the sale weighed approximately 0.1 gram each, as stated in the Information. But none of the five sachets submitted to the crime laboratory weighed close to that amount. The weights ranged from 0.0313 grams to 3.7240 grams. This suggested that the sachets examined in the laboratory were not the same items sold to the poseur-buyer.

No inventory or photographs. The police officers did not conduct a physical inventory or take photographs of the seized items, as required by Section 21(1) of RA 9165. They offered no justification for this omission.

The Court emphasized that zeal in pursuing drug peddlers is laudable, but compliance with the chain of custody rules is paramount. Without it, even the slightest doubt on the identity of the evidence renders the prosecution's case insufficient.

Practical Takeaways

• Mark evidence immediately. The moment an item is seized, the apprehending officer must mark it. This is the starting point of the chain of custody and cannot be left to memory or later reconstruction.
• Document every transfer. Every handler of the evidence must be able to testify to its receipt and turnover. Unidentified markings and unremembered initials create gaps that can destroy the prosecution's case.
• Follow Section 21 strictly. Physical inventory and photography in the presence of the accused, a media representative, a DOJ representative, and an elected public official are mandatory. If not complied with, the prosecution must explain why.
• Match the evidence. The items submitted to the laboratory must correspond to the items seized. Discrepancies in weight or markings raise serious doubts about the identity of the corpus delicti.
• For the accused and defense counsel. Gaps in the chain of custody are not mere technicalities—they go to the heart of the prosecution's burden to prove guilt beyond reasonable doubt.

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