Chain of Custody in Drug Cases: Why Marking Seized Evidence Matters

In drug-related prosecutions, the seized illegal drug is the very heart of the case. It is the corpus delicti — the body of the crime. If the prosecution cannot prove that the substance presented in court is the same one seized from the accused, the case collapses. In People v. Derilo (G.R. No. 190466, April 18, 2016), the Supreme Court acquitted an accused because the police broke the chain of custody, highlighting the strict rules that law enforcers must follow to protect the integrity of evidence.

The Facts of the Case

On November 19, 2004, police officers served a search warrant at the residence of Luis Derilo in Sorsogon. During the search, barangay tanods recovered twelve plastic sachets of suspected shabu inside a matchbox, along with alleged drug paraphernalia. The police marked the matchbox with the initials "S.B.E." but did not mark the individual plastic sachets.

The seized items were brought to the police station, then to court, and later to the PNP Crime Laboratory. A field test on the same day yielded positive results for methamphetamine hydrochloride. The following day, a forensic chemist conducted a confirmatory examination.

Derilo was charged with illegal possession of dangerous drugs and drug paraphernalia under Sections 11 and 12, Article II of Republic Act No. 9165. Both the trial court and the Court of Appeals convicted him. The Supreme Court reversed the conviction.

The Issue: Was the Chain of Custody Broken?

The central question was whether the prosecution had established an unbroken chain of custody over the seized drugs, as required by Section 21 of RA 9165. The chain of custody rule ensures that the evidence presented in court is exactly what was seized from the accused.

The Ruling: Acquittal for Broken Chain

The Supreme Court acquitted Derilo, finding that the prosecution failed to prove his guilt beyond reasonable doubt. Three critical flaws broke the chain of custody:

First, the plastic sachets were never marked at the scene. The only markings on the sachets ("A-1" to "A-12") were made by the forensic chemist a day after the seizure. The police only marked the matchbox. Marking is the first and most vital link in the chain — it prevents switching, planting, or contamination of evidence.

Second, there were unexplained discrepancies in the laboratory reports. The initial field test report stated the specimens weighed 0.3485 gram and were marked "A" through "L." The confirmatory report, however, stated a different weight of 0.3133 gram and markings "A-1" through "A-12." These inconsistencies cast doubt on whether the examined specimens were the same items seized.

Third, the prosecution failed to present testimony from key handlers. SPO1 Calupit and PO2 Lobrin, who transported the items, testified but were never asked about their handling of the evidence. An unnamed receiving officer at the crime laboratory also never testified. The Court stressed that every person who handled the evidence must testify on how they received it, what they did with it, and how they preserved it.

The Drug Paraphernalia Charge Also Failed

The Court likewise acquitted Derilo of the drug paraphernalia charge. The prosecution presented aluminum foil, a tube, and lighters, but offered no evidence that these items were fit or intended for drug use. There were no traces of shabu found on them. The mere existence of these items, without more, was insufficient for conviction.

Practical Takeaways

• Mark evidence immediately. Police officers must mark seized drugs at the scene or as soon as practicable, in the presence of the accused. Failure to do so can break the chain of custody.
• Document every link. Every person who handles seized evidence must testify about how they received it, what they did with it, and how they preserved its integrity.
• Reconcile laboratory reports. Discrepancies in weight or markings between initial and confirmatory tests can raise reasonable doubt and lead to acquittal.
• Prove intent for paraphernalia. Possession of items like aluminum foil or lighters is not enough; the prosecution must show they were intended for drug use.
• For the accused, scrutinize the evidence trail. Gaps in the chain of custody can be a powerful defense in drug cases.

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