G.R. No. 199371 February 3, 2016
Petron LPG Dealers Association and Total Gaz LPG Dealers Association, Petitioners, vs. Nena C. Ang, Alison C. Sy, Nelson C. Ang, Renato C. Ang, and/or Occupants of National Petroleum Corporation, Respondents.

FACTS

Petitioners, LPG dealers’ associations, filed a letter-complaint with the NBI alleging respondents were illegally refilling and trading various branded LPG cylinders without authorization, violating Batas Pambansa Blg. 33, as amended. The NBI, through agent Marvin de Jemil, conducted surveillance and a test-buy operation. They observed a delivery truck from a dealer, Barba Gas, enter a fenced compound marked “LPG Refilling Plant” in Magsingal, Ilocos Sur, which was linked to respondent Nation Gas. After the truck emerged, De Jemil and an asset followed it back to Barba Gas, where they successfully purchased a refilled Starflame LPG cylinder. This cylinder was then examined and documented.
Based on this operation, the NBI applied for search warrants against the Magsingal plant. The Regional Trial Court (RTC) issued Search Warrant Nos. 2005-59 and 2005-60 after conducting a searching examination of De Jemil and his asset. The CA later declared these warrants null and void, ruling that the NBI’s knowledge was derived from the complainants’ information and not from the witnesses’ own personal knowledge, which is required for probable cause.

ISSUE

Whether the Court of Appeals erred in nullifying the search warrants by ruling that the applicant’s personal knowledge was insufficiently established.

RULING

Yes, the Supreme Court reversed the CA and upheld the validity of the search warrants. The Court clarified that personal knowledge for a search warrant application is not limited to direct, first-hand observation of the criminal act itself. It can also be derived from facts personally gathered during a proper police investigation or surveillance operation. In this case, the NBI agent and his asset did not merely rely on the petitioners’ complaint. They personally conducted surveillance, witnessed the truck entering and exiting the refilling plant, and executed a test-buy, personally obtaining a refilled cylinder from the flow of commerce originating from the plant. These acts constituted a legitimate investigation that provided them with personal knowledge of the ongoing illegal activity. The facts they later presented to the judge were therefore based on their own perceptions and deductions from the surveillance, satisfying the personal knowledge requirement. The ruling in Cupcupin v. People was cited, affirming that surveillance based on a tip can yield the requisite personal knowledge if the investigating officers subsequently witness facts indicative of a crime. Thus, the RTC correctly found probable cause for issuing the warrants.