G.R. No. 87059 - People vs. Mengote y Tejas

On August 8, 1987, shortly before noon, the Western Police District received an anonymous tip of three “suspicious-looking” persons at the corner of Juan Luna and North Bay Boulevard, Tondo, Manila.
A plainclothes surveillance team, including Patrolmen Rolando Mercado and Alberto Juan, was dispatched to the scene.

The officers observed two men “looking from side to side,” one clutching his abdomen. Upon identification as police, both suspects attempted flight but were surrounded.
A search revealed a .38 caliber Smith & Wesson revolver with six live rounds on Rogelio Mengote and a fan knife on his companion, Nicanor Morellos. Both were turned over to the Intelligence Division at police headquarters.

On August 11, 1987, an information was filed charging Mengote with illegal possession of a .38 caliber S&W revolver (Serial No. 8720-T) in violation of P.D. 1866, for lack of a license or permit.
The revolver (Exhibit A), bullets (Exhibit B), and holster (Exhibit C) were admitted over defense objection. Prosecution witness Rigoberto Danganan identified the revolver as stolen during a June 13, 1987 Malabon robbery, implicating Mengote as one of the robbers.
Mengote claimed the gun was “planted” and made no proof of ownership or license. The trial court convicted him and imposed reclusion perpetua.

Whether Mengote’s warrantless arrest was lawful under Rule 113, Section 5 of the Rules of Court.
Whether the subsequent search and seizure of the revolver were valid and the weapon admissible in evidence.
Whether the testimony linking the seized revolver to the Malabon robbery was properly admitted.