Safeguarding the Chain of Custody in Drug Offenses: People v. Peralta

In drug cases, the prosecution must do more than prove that a sale or possession occurred. It must also show that the illegal drugs presented in court are the very same items seized from the accused. In People v. Peralta (G.R. No. 173472, February 26, 2010), the Supreme Court acquitted an accused because the prosecution failed to establish the chain of custody of the seized shabu. The ruling is a firm reminder that the integrity of evidence is the backbone of every drug conviction.

The Facts of the Case

On July 21, 2002, police officers from the District Drug Enforcement Group conducted a buy-bust operation against Elmer Peralta in Makati City. SPO1 Alberto Sangalang acted as the poseur-buyer and purchased a sachet of shabu from Peralta using a marked P500 bill. After the arrest, the sachet was marked "AS-1-210702" and brought to the PNP Crime Laboratory, where it tested positive for methylamphetamine hydrochloride.

At trial, the prosecution presented only Sangalang as its witness. The forensic chemist's testimony was dispensed with after the parties stipulated on the existence and due execution of the Chemistry Report. Peralta denied the charge, claiming he was arrested without a warrant while sleeping. The Regional Trial Court convicted him, and the Court of Appeals affirmed. On appeal, the Supreme Court reversed.

The Issue: Was the Chain of Custody Proven?

The central issue was whether the prosecution presented ample proof that Peralta sold illegal drugs, which required establishing the existence of the corpus delicti—the body of the crime. For drug offenses, the corpus delicti is the seized substance itself, and its integrity must be preserved from seizure to presentation in court.

The Ruling: Integrity of Evidence Is Non-Negotiable

The Supreme Court held that the prosecution failed to prove the chain of custody. The Court pointed out several fatal gaps in the evidence:

• No evidence of when the sachet was marked. The prosecution did not ask Sangalang if he made the marking "AS-1-210702" or when it was done. The sachet could have been marked long after seizure or even after laboratory testing.
• No proof of sealing. The seizing officer did not testify that the sachet was sealed to prevent tampering or substitution before it reached the laboratory.
• No testimony from the receiving officers. The prosecution did not present the desk officer, courier, or laboratory technician who handled the sachet. Each link in the chain was left unexplained.

The Court emphasized that seized drugs are not readily identifiable by sight or touch and can easily be tampered with. Thus, the prosecution must present testimony about every link in the chain—from seizure to laboratory examination to court presentation.

The Presumption of Regularity Cannot Save a Weak Case

The Court rejected the argument that the presumption of regularity in the performance of official duties could cure the gaps. Once the defense challenges the chain of custody, the presumption of regularity cannot prevail over the presumption of innocence. The Court also noted that a stipulation on the Chemistry Report only proves the authenticity of the report, not that the substance tested was the same one seized from the accused.

Practical Takeaways

• Mark and seal immediately. Seizing officers should mark the seized item at the earliest opportunity and seal it, preferably with adhesive tape that leaves visible tears if removed.
• Document every handoff. The prosecution must present testimony from every person who handled the drugs—from the seizing officer to the desk officer to the courier to the laboratory technician.
• Ask the right questions. Prosecutors must elicit specific details: who marked the item, when, what the markings mean, and how the item was protected from tampering.
• Laboratory technicians must reseal. After testing, the technician should seal the item again so that any retest would examine the same substance.
• A stipulation is not a substitute. Agreeing on a laboratory report does not prove the chain of custody; it only proves the report's authenticity.

Conclusion

People v. Peralta is a cautionary tale for law enforcement and prosecutors alike. A conviction for drug offenses rises or falls on the integrity of the seized evidence. Without a meticulously documented chain of custody, even a positive laboratory finding cannot sustain a conviction. The Court's acquittal of Peralta underscores that the presumption of innocence demands nothing less.

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