G.R. No. 171713 - Estate of Ong vs. Diaz

On April 17, 2015, during the conduct of Oplan Sita in the City of Manila, members of the V. Mapa Police Station observed a yellow Mitsubishi Lancer without an official plate number.
PO3 Ruel Aguilar flagged down the vehicle and approached the driver, Hermie Estolano y Castillo, who failed to produce his driver’s license and the vehicle’s registration documents.
After initial resistance and an apparent attempt to conceal something in his pocket, Estolano eventually alighted from the vehicle under police orders.

PO1 Sonny Boy Lubay, while conducting a body search on Estolano, observed him reaching into his right front pocket.
PO1 Lubay noticed Estolano holding the pin of an MK2 Fragmentation Hand Grenade marked “HEC”.
To prevent a potential explosion, PO1 Lubay, along with PO1 Lucky Samson, restrained Estolano.
A search of the vehicle revealed additional irregularities, including an improvised rear plate with the word “SUPREMA” and the official plate number PFG-453.
The confiscated grenade was processed by police investigators: SPO1 Benigno Lino Corado Jr. initially received it, and later SPO1 Allan Salinas of the Explosives Ordnance Division applied a masking tape and marked it “HEC”.

SPO1 Salinas issued a certificate confirming that the grenade’s main components were intact and capable of explosion.
Additional certification from P/C Supt. Elmo Francis O. Sarona of the Firearms and Explosives Office confirmed that Estolano had no permit or license to possess the grenade.
Estolano denied the charge, asserting that he had attended a birthday celebration in Mandaluyong City on April 16, 2015, and that he was returning home with friends when stopped at the checkpoint.

During the incident, Estolano alleged that he was subjected to physical abuse, including being kicked in the stomach, and was coerced by police.
He claimed the police demanded P2,000,000.00 for bail and that among his friends, only he was charged while others were seemingly exempt.
Estolano maintained that these irregularities involved excessive use of authority and deviated from prescribed police procedure.

Estolano entered a plea of not guilty, but after trial, the Regional Trial Court (RTC) convicted him of illegal possession of a hand grenade under PD 1866 as amended by RA 9516, sentencing him to reclusion perpetua.
The Court of Appeals (CA) later affirmed the RTC’s conviction, relying on the testimonies of various police officers and the presumption of regular performance of their duties.
The defense raised several issues on appeal:

The credibility of PO1 Lubay’s testimony regarding the discovery of the grenade.
The admissibility of the grenade as evidence, contending that it was confiscated through an invalid, warrantless search.
The absence of evidence that Estolano had been properly certified as unlicensed to possess such a weapon at the time charges were filed.

The Public Attorney’s Office and the Office of the Solicitor General filed respective appeals and supplemental briefs contesting the conviction.

The prosecution argued that the search was justified as part of a routine checkpoint stop, a practice allowed without a warrant during moving vehicle inspections.
However, the Court noted that the scope of a valid warrantless search on moving vehicles is strictly limited to a visual inspection for traffic violations and does not extend to an extensive or invasive body search.
The absence of proper documentation or authorization regarding the implementation of the checkpoint (Oplan Sita) further cast doubt on the legality of the search.

Whether the extensive search conducted on Estolano, which went beyond a mere visual inspection, violated his constitutional right against unreasonable searches and seizures.
Whether the hand grenade seized during the extensive search is admissible as evidence given that its discovery resulted from a procedure not justified by the limitations imposed on warrantless searches.
Whether a traffic violation alone can provide sufficient probable cause to authorize an extensive body search and subsequent arrest.
Whether the procedural irregularities, such as the lack of proper checkpoint authorization and after-action documentation, negate the legality of the evidence obtained.