G.R. No. L-33140 - J. M. Tuason and Co., Inc. vs. Mariano

Accused-appellant Marlon Abetong y Endrado was charged with violating Section 5, Article II of Republic Act No. 9165 (the Comprehensive Dangerous Drugs Act of 2002) for allegedly selling dangerous drugs.
The charge arose from a buy-bust operation conducted on August 22, 2003, in Bacolod City where the accused allegedly sold a heat-sealed transparent plastic packet containing methylamphetamine hydrochloride (shabu) in exchange for marked money (two PhP 50 bills).
The prosecution’s Information specified that the drug weighed 0.02 gram(s) more or less, while subsequent forensic examination noted the specimen weighed 0.04 gram, thereby highlighting an early discrepancy in the evidence.

Upon receiving an information tip, Police Officer 3 (PO3) Wilfredo Perez, designated as the poseur-buyer, and his team executed the buy-bust operation at the accused’s residence in Purok Sigay, Barangay 2, Bacolod City.
During the operation, after making the purchase with marked money, PO3 Perez collected the plastic sachet containing the white crystalline substance and a tooter, later noting that four individuals were present for a "pot session" inside the premises.
The seized items were secured by PO3 Perez who placed them in the evidence locker of the Drug Enforcement Unit, the access to which was controlled exclusively by Police Inspector Jonathan Lorilla.
The evidence, particularly the drug sachet and tooter, was not immediately brought to the Philippine National Police (PNP) Crime Laboratory but was only delivered on August 25, 2003—three days after its seizure—raising concerns over possible contamination or tampering.

Inspector Augustina Ompoy, the Forensic Chemical Officer at the Regional PNP Crime Laboratory, conducted qualitative and quantitative tests on the seized specimen.
The tests confirmed the presence of methamphetamine hydrochloride; however, a discrepancy in the weight arose, with the Information charging the accused for selling 0.02 gram(s) while the laboratory test recorded 0.04 gram.
Such inconsistency called into question whether the specimen tested was exactly the same as that confiscated by the police.

The accused contended that his arrest was illegal as he was taken unawares while at home, and no drugs were found on his person—only that he was seized along with three other individuals who were engaged in a pot session.
Abetong maintained that he was not informed of the charges until his arraignment, and his defense further argued that critical procedural requirements had been neglected, particularly in the handling and documentation of the seized drugs.
A key part of his defense was the assertion that the police failed to secure the chain of custody, primarily because only PO3 Perez testified regarding the custody of the evidence; the key-holder, Inspector Lorilla, did not testify, thus leaving gaps in the documentation of how the drug evidence was handled over the period.

At trial, the Regional Trial Court (RTC) Branch 47 in Bacolod City found the evidence sufficient and convicted the accused-appellant, sentencing him to life imprisonment, a fine of PhP 500,000.00, and the accessory penalties provided by law.
The Court of Appeals (CA) affirmed the RTC’s decision, holding that despite certain procedural lapses, the integrity of the evidence was presumed to have been maintained.
On appeal, the Supreme Court reviewed the evidentiary chain of custody and other procedural irregularities, ultimately finding serious discrepancies that undermined the prosecution’s case.

Whether the non-compliance with Section 21 of RA 9165—specifically, the failure to inventory, photograph, and document the chain of custody of the confiscated drugs—undermined the integrity of the evidence.
Whether the delay in transferring the seized items from the evidence locker to the PNP Crime Laboratory (three days instead of within 24 hours) compromised the evidentiary value and authenticity of the specimen.
Whether the absence of testimony from the sole key-holder, Police Inspector Jonathan Lorilla, created an unbridgeable gap in the chain of custody necessary to prove that the drug evidence was controlled and unaltered.
Whether the discrepancy between the weight of the drug as stated in the Information (0.02 gram[s]) and the weight determined by forensic analysis (0.04 gram) casts doubt on the identification and integrity of the corpus delicti.
Whether the reliance on the testimony of a single prosecution witness (PO3 Perez), despite facing contradictions in his statements and forensic evidence, is sufficient to establish guilt beyond reasonable doubt in a narcotics case.