Chain of Custody in Drug Cases: How a Marking Error Can Lead to Acquittal

The Supreme Court recently acquitted two accused in a drug case because of a fatal flaw in the chain of custody: an altered marking in the documents. The case of People v. Valencia y Lorenzo (G.R. No. 250610, July 10, 2023) serves as a stark reminder that even a minimal change in the marking of seized drugs can break the chain of custody and cast reasonable doubt on the identity and integrity of the corpus delicti—the very body of the crime.

For a conviction for illegal sale of dangerous drugs to stand, the prosecution must prove two things beyond reasonable doubt: (1) that the transaction actually took place, and (2) that the identity and integrity of the seized drugs were preserved. The second requirement is where the prosecution in this case failed.

The Facts of the Case

In January 2016, police officers in Dumaguete City conducted a buy-bust operation against Ryan Antipuesto and Francis Valencia. A poseur buyer was introduced to Antipuesto, who agreed to sell PHP 10,000.00 worth of shabu. At the meeting point, Valencia handed the plastic sachet of shabu to the poseur buyer, who then arrested Valencia. Antipuesto escaped.

The arresting officer marked the seized sachet with "FLV/RA-BB-01-16-16" and placed it in a brown envelope. The inventory and photographing were done at the police station, not at the place of arrest, because of the number of large vehicles exiting the port.

At the crime laboratory, the forensic chemist noticed that the marking on the specimen did not match the marking stated in the Letter Request. The letter indicated the marking as "FLV/RA-BB-01-16-2016," but the specimen bore "FLV/RA-BB-01-16-16." Instead of flagging the discrepancy, the chemist allowed the arresting officer to alter the letter—striking off the "20" from "2016" to make it appear as "16."

Both the trial court and the Court of Appeals convicted the accused. The Supreme Court reversed.

The Issue

The central issue was whether the prosecution had established the identity and integrity of the corpus delicti, given the irregularities in the chain of custody.

The Ruling: Marking Errors Are Fatal

The Supreme Court acquitted the accused. While the Court found that the buy-bust transaction did occur, it ruled that the prosecution failed to establish an unbroken chain of custody.

The Court reiterated that marking is a crucial step in the chain of custody. It is the reference point for all succeeding handling of the seized drugs. Marking should be done immediately upon seizure to preserve the integrity of the evidence as it enters the chain.

The fatal error here was the alteration of the Letter Request. The chemist allowed the arresting officer to change the marking stated in the letter to match the specimen. The Court held that receipts showing the chain of custody cannot be altered or modified while the specimen is in transit to the next custodian. Even a minimal change in the marking is fatal to the identity and integrity of the corpus delicti.

The Court also noted that the inventory and photographing were done at the police station, not at the place of arrest. While the law allows an alternative venue under Section 21 of Republic Act No. 9165, as amended by Republic Act No. 10640, the arresting officers must provide a justifiable reason. The explanation that large vehicles were exiting the port was deemed a generic statement that did not sufficiently explain why the inventory could not be done at the place of arrest.

The Saving Clause Cannot Save a Broken Chain

The Court emphasized that the saving clause under Section 21 cannot be invoked unless the prosecution first acknowledges and justifies the deviation from the required procedure. The prosecution must prove that the integrity and evidentiary value of the seized items were properly preserved. In this case, the alteration of the marking broke the chain, and the prosecution could not rely on the presumption of regularity to salvage its case.

Practical Takeaways

• Marking is critical. The marking of seized drugs must be done immediately at the place of seizure. It serves as the foundation of the entire chain of custody.
• Do not alter documents. Receipts, letter requests, and other documents showing the chain of custody must not be altered or modified. Even a minor correction can break the chain and lead to acquittal.
• Justify deviations. If the inventory and photographing are done at an alternative venue, the arresting officers must provide a sensible, practicable, and specific justification—not a generic excuse.
• The saving clause has limits. The prosecution cannot invoke the saving clause unless it first acknowledges and explains any deviation from Section 21 of RA 9165, and proves that the integrity of the evidence was preserved.
• For the accused, scrutinize the chain. Defense counsel should carefully examine the markings, documents, and testimonies regarding the chain of custody. Any unexplained alteration or break can be the basis for acquittal.

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