Chain of Custody in Drug Cases: What People v. Nacua Teaches About Safeguarding Evidence

The Supreme Court's 2013 decision in People v. Nacua (G.R. No. 200165, January 30, 2013) is a reminder that in drug prosecutions, procedure is not a technicality — it is the shield that protects the identity of the drug itself. When police fail to follow the chain of custody rules under Republic Act No. 9165, the Dangerous Drugs Act of 2002, the evidence can be rendered worthless, and a conviction cannot stand.

Why the Drug Itself Is the Case

In prosecutions involving dangerous drugs, the prohibited substance is the corpus delicti — the body of the offense. As the Court explained, sale or possession of a dangerous drug can never be proven without seizure and identification of the drug. The fact of its existence is vital to sustain a conviction beyond reasonable doubt.

This matters because drugs are uniquely vulnerable evidence. They are indistinct, not readily identifiable, and easily susceptible to tampering, alteration, or substitution. That is why the law prescribes strict measures for handling seized drugs from the moment of seizure until their presentation in court.

The Rules Under Section 21 of RA 9165

Section 21(1) of RA 9165 requires that the apprehending team, immediately after seizure and confiscation, physically inventory and photograph the drugs in the presence of:

• the accused or the person from whom the items were seized, or their representative or counsel;
• a representative from the media;
• a representative from the Department of Justice; and
• any elected public official.

These witnesses must sign the copies of the inventory and be given a copy. The Implementing Rules and Regulations (IRR) of RA 9165 add that the physical inventory and photograph should be conducted at the place where the search warrant is served, or at the nearest police station or office in case of warrantless seizures.

The rules also allow flexibility: non-compliance under justifiable grounds does not automatically invalidate the seizure, provided the integrity and evidentiary value of the seized items are properly preserved. But the Court has been clear that this exception requires both a valid explanation and proof that the evidence was safeguarded.

What Happened in Nacua

Police received information that Reynaldo Nacua and his common-law wife were selling shabu. After surveillance, officers conducted a "test-buy" on September 2, 2005, during which they allegedly bought a sachet of shabu from the couple for P200. The officers did not arrest the couple. Instead, they returned to the police station, where the sachet was marked with the initials "RN" and sent for forensic examination. It tested positive for methamphetamine hydrochloride.

Armed with this result, police applied for and obtained a search warrant. On September 21, 2005, they searched the couple's residence and seized more suspected shabu and drug paraphernalia. Nacua was arrested and later convicted by the trial court, a conviction affirmed by the Court of Appeals.

The Court's Ruling: Total Disregard of Procedure

The Supreme Court reversed and acquitted Nacua. It found a total disregard of the requirements of law and jurisprudence.

First, the police marked the sachet only at the police station, not immediately upon seizure and not in the presence of the accused or any disinterested witnesses. Citing People v. Coreche (G.R. No. 182528, August 14, 2009), the Court stressed that marking must be done immediately after seizure because it is the starting point of the custodial chain. Failure to mark promptly raises reasonable doubt about the authenticity of the corpus delicti.

Second, the prosecution offered no explanation for the non-compliance. The Court observed that the operation appeared intended only to secure a search warrant — there was no original plan to arrest and charge the couple for that day's purchase. Yet the prosecution inexplicably chose to indict them for the test-buy rather than for the results of the September 21 search.

Third, the prosecution failed to show how the sachet was kept and by whom after forensic examination until its presentation in court. With the integrity of the drug unproven, reasonable doubt required acquittal.

Practical Takeaways

• Marking must be immediate. The seized drug should be marked right after confiscation, in the presence of the accused or their representative, because this begins the chain of custody.
• Inventory and photograph with witnesses. Section 21 of RA 9165 requires the presence of the accused or counsel, a media representative, a DOJ representative, and an elected public official.
• Non-compliance needs justification. Relaxation of the rules is allowed only for compelling reasons and only if the integrity and evidentiary value of the drugs are shown to have been preserved.
• The unbroken chain matters. The prosecution must account for every link — from seizure to laboratory examination to court presentation — including who held the specimen and how it was stored.
• Procedure protects the innocent. Even a valid arrest can collapse if the evidence connecting the accused to the drug cannot be trusted.

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