Chain of Custody Gaps Lead to Acquittal in Drug Case: People v. Guanzon

In drug cases, 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. The Supreme Court, in People v. Guanzon (G.R. No. 233653, September 5, 2018), acquitted an accused after finding that the police failed to establish an unbroken chain of custody over the seized shabu. The ruling is a reminder that strict compliance with Section 21 of Republic Act No. 9165 is essential to protect the accused's constitutional right to be presumed innocent.

The Facts of the Case

On July 28, 2003, police officers in Antipolo City conducted a buy-bust operation against Ricardo Guanzon based on information that he was selling drugs. PO2 Hernandez acted as the poseur-buyer and purchased one plastic sachet of shabu for P200. After the arrest, PO3 Paulos frisked Guanzon and recovered another sachet and the marked money.

At the police station, PO2 Hernandez marked the bought sachet as "A" and the confiscated sachet as "B." Both were submitted to the PNP Crime Laboratory, which confirmed they contained methamphetamine hydrochloride (shabu). Guanzon was charged with illegal sale and illegal possession of dangerous drugs under Sections 5 and 11 of RA 9165.

The defense claimed Guanzon was arrested inside a friend's house, not in a buy-bust operation, and that police planted the drugs.

The Issue

The central question was whether the prosecution proved Guanzon's guilt beyond reasonable doubt despite the police's failure to comply with the mandatory requirements of Section 21 of RA 9165 on the custody and disposition of seized drugs.

The Ruling: Acquittal Due to Broken Chain of Custody

The Supreme Court reversed the conviction and acquitted Guanzon. The Court emphasized that in drug cases, the corpus delicti—the illegal drug itself—must be established beyond reasonable doubt. The prosecution must prove the identity of the seized drug and show that its integrity was preserved from seizure to presentation in court.

Under Section 21 of RA 9165, as amended by RA 10640, the apprehending team must immediately conduct a physical inventory and photograph the seized items in the presence of the accused or his representative, an elected public official, and a representative of the National Prosecution Service or the media. Non-compliance may be excused only under justifiable grounds, provided the integrity and evidentiary value of the seized items are preserved.

The Court found several fatal gaps in the chain of custody:

Contradictory testimonies on custody. PO3 Paulos testified that he turned over the confiscated sachet to team leader SPO2 Abalos. But SPO2 Abalos testified that PO3 Paulos kept possession of the sachet from the arrest area to the police station. This contradiction cast doubt on whether the drugs presented in court were the same ones seized from Guanzon.

Unclear marking of evidence. No witness clearly established who marked the seized drugs, where the marking took place, or when it was done. PO2 Hernandez, who allegedly did the marking, never testified about handling the drugs after the arrest. The forensic chemist said the specimens were already pre-marked when submitted to her.

Absence of inventory and photographs. The prosecution did not present any inventory or photographs of the seized items. SPO2 Abalos could not even confirm whether an inventory was prepared.

The Court cited People v. Villar (799 Phil. 378 [2016]), which outlined the four links that must be established in a chain of custody: (1) seizure and marking of the drug by the apprehending officer; (2) turnover to the investigating officer; (3) turnover to the forensic chemist for examination; and (4) turnover and submission of the marked drug to the court.

Here, the first two links were broken. The Court noted that marking should be done immediately upon confiscation, in the presence of the accused, to prevent switching, planting, or contamination of evidence.

Practical Takeaways

• Strict compliance is required. Police must follow Section 21 of RA 9165, as amended, including immediate marking, inventory, and photographing of seized drugs in the presence of required witnesses.
• The prosecution must explain any gap. If the police fail to comply with the requirements, the prosecution must present justifiable grounds and prove that the integrity of the evidence was preserved.
• Minor inconsistencies matter less than gaps in custody. Contradictions that affect the identity and handling of the seized drugs are not mere peripheral matters—they can be fatal to the prosecution's case.
• Marking is the critical first link. The marking of seized drugs must be done immediately and in the presence of the accused to ensure the evidence is not tampered with.
• The burden is on the State. In drug cases, the prosecution must prove every link in the chain of custody beyond reasonable doubt, just like the elements of the offense.

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