Chain of Custody in Drug Cases: When Police Lapses Lead to Acquittal

In a significant ruling on drug prosecutions, the Supreme Court acquitted an accused of illegal sale and possession of dangerous drugs because the prosecution failed to establish an unbroken chain of custody over the seized marijuana. The case of People v. De Guzman (G.R. No. 219955, February 5, 2018) underscores a fundamental rule: in drug cases, the drug itself is the corpus delicti—the body of the crime—and its identity must be proven with moral certainty.

The Facts of the Case

On November 12, 2009, police conducted an entrapment operation against Glenn De Guzman in Olongapo City. A poseur-buyer purchased a sachet of marijuana for ₱100.00 in marked money. After the exchange, the accused was arrested, and a body search yielded four more sachets and a plastic pack of marijuana.

The seized items were marked at the police station, not at the scene of arrest. An inventory was conducted with only two barangay officials present—no representatives from the Department of Justice or the media. The items were later turned over to the crime laboratory, which confirmed they contained marijuana. The trial court convicted De Guzman, and the Court of Appeals affirmed. The Supreme Court reversed.

The Issue

The central question was whether the chain of custody over the seized drugs remained unbroken despite the arresting officers' failure to strictly comply with Section 21, Article II of Republic Act No. 9165 (the Comprehensive Dangerous Drugs Act of 2002). Specifically, the police failed to mark the items at the crime scene and did not secure DOJ and media representatives during the inventory.

The Chain of Custody Rule

Section 21 requires that, immediately after seizure, the apprehending team conduct a physical inventory and photograph the items in the presence of the accused (or his representative or counsel), an elected public official, and a representative of the National Prosecution Service or the media. These witnesses must sign the inventory.

The Supreme Court emphasized that strict compliance is essential. However, non-compliance does not automatically result in acquittal. The law contains a saving mechanism: lapses may be excused under "justifiable grounds," provided the integrity and evidentiary value of the seized items are properly preserved.

For this saving mechanism to apply, the prosecution must: (1) recognize and explain the lapses committed by the apprehending team, and (2) demonstrate that the integrity and evidentiary value of the evidence were preserved despite the procedural failures.

The Fatal Gaps in This Case

The prosecution failed on both counts. It neither explained the procedural lapses nor adequately proved the chain of custody. The Court identified specific gaps:

First link (seizure and marking). The testimonies were silent on who had custody of the items from the place of arrest until they reached the police station.

Third link (turnover to the forensic chemist). The investigating officer claimed he delivered the items to the crime laboratory, but a certain "PO1 Menor" received them. Neither PO1 Menor nor anyone else testified about this transfer.

Fourth link (turnover to court). The forensic chemist never testified. The parties merely stipulated on her findings. Worse, the crime laboratory turned over the drugs to the City Prosecutor's Office before trial—an entity that has no role in the chain of custody of dangerous drugs.

Because these official acts were patently irregular, the Court ruled that the presumption of regularity in the performance of official duties could not be applied in the prosecution's favor.

Practical Takeaways

• Mark items at the scene. Seized drugs should be marked immediately at the place of arrest, not later at the police station, whenever practicable.

• Secure required witnesses. The inventory must be conducted in the presence of the accused (or representative/counsel), an elected public official, and a DOJ or media representative.

• Document every transfer. Every person who handles the evidence must testify as to how and from whom it was received, what happened to it, and the condition in which it was delivered to the next link.

• Explain any lapse. If compliance is impossible, the prosecution must offer justifiable grounds and prove that the drugs' integrity was preserved.

• Keep the chain simple. Custody should move from the seizing officer to the investigating officer, to the forensic chemist, and then to the court—not through unnecessary intermediaries like a prosecutor's office.

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