G.R. No. 188165 - People vs. Sandiganbayan

May 19, 2003: A confidential police agent negotiated by cellular phone with appellant for the purchase of shabu. The agent reported to PDEA, Philippine Army intelligence, and local police, furnishing appellant’s name, physical description, and expected arrival in Baler, Aurora.
May 20, 2003: At 11:00 a.m., appellant informed the agent he was on a Genesis bus, en route to arrive wearing a red-white striped T-shirt. A multi-agency team took posts along the highway.

At about 3:00 p.m., appellant alighted from the bus, was identified by the agent, and as he awaited a tricycle, police approached him on suspicion of carrying shabu. While being led away, a white envelope slipped from his pocket, revealing a sachet of suspected drugs.
Appellant was brought to the station. Inspector De Vera marked the sachet in appellant’s presence; field and laboratory tests confirmed methamphetamine hydrochloride.

Appellant was charged under R.A. 9165: Section 5 (transporting or delivering) and Section 11 (possession). He pleaded not guilty, denied the charges, and claimed an unlawful arrest and planting of evidence.
RTC (July 8, 2004) convicted under Section 5 (life imprisonment plus ₱500,000 fine) and acquitted under Section 11. CA (May 22, 2008) affirmed. Appellant appealed to the Supreme Court.

Whether appellant’s warrantless arrest was lawful and whether failure to object constitutes waiver.
Whether the subsequent warrantless search and seizure of the sachet complied with constitutional requirements.

Whether the specimen was properly identified and marked to establish chain of custody.
Whether the sachet is admissible or should be excluded as “fruit of the poisonous tree.”