G.R. No. 251693 - Salas vs. Bunyi-Medina

On March 28, 2011, at around 7:05 p.m. in Butuan City, Philippines, a buy-bust operation was conducted targeting illegal drug transactions.
Accused-appellants Celso Plaza y Caenglish (alias “Joboy Plaza”) and Joseph Guibao Balinton (alias “Joabs”) were implicated in the alleged sale of one (1) sachet of methamphetamine hydrochloride (shabu) weighing 0.0524 gram for a consideration of ₱500.00.
The operation was conducted near the Iglesia Ni Cristo church, a location noted to be poorly lit, which plays a significant role in the defense’s argument regarding the evidentiary details.

PDEA Agent Alex B. Subang – served as the poseur-buyer and was the primary eyewitness establishing the transaction.
PDEA Agent Simplicio Cubero Bautista – acted as the arresting officer and later assisted in the investigation and documentation process.
Police Senior Inspector Joel P. Signar – provided laboratory evidence through stipulated testimony regarding the examination of the sachet and the accused’s urine samples.
Barangay Captain Ramonita M. Boholano – witnessed the inventory of drugs and the signing of the Certificate of Inventory.

During the operation, Plaza displayed the procedure by retrieving a sachet from his belt bag and passing it to Balinton, who handed it—wrapped in aluminum foil—to PDEA Agent Subang.
After the transaction, a chase ensued with both accused resisting arrest, leading to a scuffle that involved bystanders and necessitated further investigation at the PDEA office.

The prosecution’s case was built on the detailed testimony of PDEA Agent Subang, which described:

The planning and execution of the buy-bust operation.
The explicit details of the transaction, including the asking price of ₱500.00, the handling of the shabu, and the sequence of handovers among the accused and agents.

Other witnesses (PDEA Agent Bautista, PSInsp. Signar, and Barangay Captain Boholano) corroborated the events through their depositions concerning the physical evidence and the procedural aspects of the seizure.
The defense, while testifying for themselves, argued that inconsistencies in Agent Subang’s testimony and the omission of immediate evidence-marking procedures cast doubt on the credibility of the prosecution’s evidence.

The seized sachet of shabu was subject to a chain of custody requirement under Section 21 of R.A. No. 9165, intended to ensure the integrity of the evidence from seizure to presentation in court.
While the first three links of the chain of custody (seizure, turnover to an investigating officer, and submission to the forensic laboratory) were substantially complied with, questions arose over the fourth link concerning:

The identification of the person who delivered the evidence from the forensic chemist to the court.
The procedures for the handling, storing, and safeguarding of the sachet from its arrival at the lab to its presentation in court.

The prosecution admitted that due to security and logistical considerations—particularly, the presence of an agitated crowd—the team departed the scene hastily and completed the evidence-marking later at the PDEA office, invoking an exception under justifiable grounds.

Whether there was a bona fide buy-bust operation conducted by the PDEA despite the poor lighting and alleged inconsistencies in the eyewitness testimony.
Whether the identification of the accused-appellants during the transaction was sufficiently established despite challenges posed by the conditions at the scene.

Whether the law enforcement officers complied with Section 21 of R.A. No. 9165 regarding the chain of custody of the seized sachet of shabu, particularly in marking, inventorying, and photographing the item immediately after seizure.
Whether the evidentiary gaps in the chain, especially the failure to fully document the fourth link (the transfer from the forensic chemist to the court), created reasonable doubt as to the integrity of the evidence.