Evidence obtained through a warrantless search based merely on an unverified tip from an informant or a third party's suspicion, without independent observation of suspicious activity by the police officer establishing a genuine reason, does not constitute a valid "stop and frisk" search, and such illegally seized evidence is inadmissible under the exclusionary rule.

The case arose within the context of law enforcement efforts against illegal drug trafficking, specifically involving the transportation of marijuana in the province of La Union. Police acted based on a text message from an unidentified civilian informant regarding the transport of marijuana by a named individual, leading to the establishment of a checkpoint and the subsequent apprehension and search of the accused.

• PSI Bayan received a text message from an unidentified informant that a certain "Marvin Buya" would be transporting marijuana from Barangay Lun-Oy to the Poblacion of San Gabriel, La Union.
• PSI Bayan ordered SPO1 Taracatac to set up a checkpoint; no description of Marvin Buya was provided, only the name.
• A jeepney arrived, and the driver signalled to SPO1 Taracatac, indicating two male passengers later identified as Victor Cogaed (appellant) and Santiago Dayao.
• Cogaed was carrying a blue bag and a sack; Dayao had a yellow bag.
• SPO1 Taracatac approached Cogaed and Dayao, asking about the contents of their bags.
• Cogaed and Dayao stated they didn't know the contents as they were merely transporting the bags for their barriomate "Marvin."
• SPO1 Taracatac asked Cogaed to open the blue bag; Cogaed opened it, revealing bricks of suspected marijuana.
• Cogaed allegedly muttered in Ilocano that "Marvin is a fool."
• SPO1 Taracatac arrested Cogaed and Dayao and brought them to the police station.
• At the station, PO3 Campit asked them to empty their bags; Cogaed's sack contained marijuana fruiting tops, and Dayao's bag contained a brick of marijuana.
• The total weight of marijuana seized from both was 17,429.6 grams.
• Cogaed testified he was going to the market to buy pesticide, boarded a jeepney, recognized Dayao, and upon alighting, Dayao asked for help carrying a travelling bag and a sack, which he agreed to.
• Cogaed claimed SPO1 Taracatac approached them, asked what was inside, he replied he didn't know, and the officer arrested them. He also claimed the officer hit him on the head at the station and opened the bags without his knowledge of the contents.
• The case against Dayao (14 years old) was dismissed under the Juvenile Justice and Welfare Act.

• The trial court gravely erred in admitting the seized dangerous drugs as evidence because they were obtained through an unlawful warrantless search and seizure.
• The "stop and frisk" search was invalid as there was no reasonable suspicion based on the police officer's personal observation; the officer relied solely on the jeepney driver's signal.
• The search could not be justified as incidental to a lawful arrest because the arrest itself was illegal, as Cogaed was not committing, attempting to commit, or had just committed a crime in the officer's presence.
• There was no valid waiver of the right against unreasonable searches; Cogaed's act of opening the bag was not voluntary but done under coercive circumstances, without being fully informed of his rights or the consequences of his inaction.
• The arresting officers failed to comply with the requirements for the proper custody (chain of custody) of seized dangerous drugs under Republic Act No. 9165.
• The integrity and evidentiary value of the seized dangerous drugs were compromised due to the arresting officer's failures.

• The search and seizure were valid as Cogaed consented to the search by voluntarily opening his bag without prompting from SPO1 Taracatac after the officer identified himself.
• Cogaed waived his right to object to the irregularity of his arrest and the search when he did not protest when asked to open his bag.
• The warrantless search was justified under the circumstances, approximating a valid "stop and frisk" or search incidental to arrest given the information received and the context of drug transport.
• The prosecution successfully proved Cogaed's guilt beyond reasonable doubt for illegal possession of marijuana.

• Whether the warrantless search and seizure conducted by the police officers violated Cogaed's constitutional right against unreasonable searches and seizures.
• Whether the seized marijuana is admissible as evidence against Cogaed.
• Whether Cogaed validly waived his constitutional right against unreasonable searches.
• Whether there is sufficient admissible evidence to sustain Cogaed's conviction.

• The warrantless search and seizure were unconstitutional and invalid; the police action did not qualify as a legitimate "stop and frisk" because SPO1 Taracatac had no personal knowledge or observation of any facts leading to a reasonable suspicion that Cogaed was committing a crime, relying instead on the jeepney driver's indication.
• The search cannot be justified as incidental to a lawful warrantless arrest, as Cogaed was not committing, attempting, or had just committed a crime in the officer's presence (in flagrante delicto), nor did the officer have personal knowledge for a "hot pursuit" arrest; thus, the arrest itself was unlawful.
• Cogaed did not validly waive his right against unreasonable search; mere passive conformity or silence in a coercive environment created by police presence does not constitute intelligent, knowing, and voluntary consent. The police failed to inform Cogaed that his inaction would be deemed consent or ensure he understood his rights.
• The marijuana seized during the illegal search is inadmissible in evidence under the exclusionary rule (fruit of the poisonous tree doctrine) provided in Article III, Section 3(2) of the Constitution.
• Due to the inadmissibility of the seized marijuana, there is no sufficient evidence to prove Cogaed's guilt beyond reasonable doubt.
• The Court reversed the decisions of the RTC and CA and acquitted Victor Cogaed.

• Right Against Unreasonable Searches and Seizures (Art. III, Sec. 2, Constitution): This fundamental right protects individuals' persons and effects from unreasonable state intrusion. The Court emphasized its importance for autonomy and privacy, stating that warrantless searches are generally unreasonable, subject only to specific exceptions. In this case, the Court found the search unreasonable as it did not fall under any valid exception.
• Warrantless Search Exceptions: The Court enumerated established exceptions (search incidental to lawful arrest, plain view, moving vehicle, consented search, customs search, stop and frisk, exigent circumstances). It specifically analyzed and rejected the applicability of stop and frisk, search incidental to lawful arrest, and consented search to the facts of this case.
• Stop and Frisk (Terry Search): Defined as a limited protective search for weapons based on a police officer's reasonable suspicion, grounded in specific, articulable facts observed by the officer, that criminal activity may be afoot and the person is armed and dangerous. The Court ruled this doctrine inapplicable because the officer's suspicion was based on a third party's (driver's) signal, not personal observation, and there was no indication Cogaed was acting suspiciously or was armed. The Court stressed it requires a "genuine reason," not mere suspicion or a hunch.
• Search Incidental to Lawful Arrest (Rule 126, Sec. 13, Rules of Court): Allows a warrantless search of a person lawfully arrested to find dangerous weapons or evidence related to the crime. The Court found this inapplicable because the prerequisite lawful arrest (under Rule 113, Sec. 5) was absent; Cogaed was not committing a crime in the officer's presence (in flagrante delicto) when arrested.
• Consented Warrantless Search: Requires clear and convincing evidence that consent was freely, intelligently, and voluntarily given, without duress or coercion. The Court held that Cogaed's opening of the bag under the circumstances (presence of police, being asked questions) constituted mere passive conformity in a coercive environment, not a valid waiver, especially since he wasn't informed of his right to refuse. The burden is on the state to prove valid consent.
• Exclusionary Rule (Fruit of the Poisonous Tree Doctrine) (Art. III, Sec. 3(2), Constitution): Mandates that any evidence obtained in violation of the right against unreasonable searches and seizures is inadmissible for any purpose in any proceeding. The Court applied this rule strictly, excluding the illegally seized marijuana, which formed the basis of Cogaed's conviction.
• Probable Cause vs. Reasonable Suspicion: The Court distinguished the levels of justification required for different police actions. While probable cause is needed for warrants and warrantless arrests (except in flagrante delicto), a "stop and frisk" requires only reasonable suspicion based on the officer's personal observation and experience, which must be more than a mere hunch but less than probable cause. The Court found neither standard was met for the actions taken against Cogaed prior to opening the bag.

• "The mantle of protection upon one's person and one's effects through Article III, Section 2 of the Constitution is essential to allow citizens to evolve their autonomy and, hence, to avail themselves of their right to privacy."
• "This was not a reasonable search within the meaning of the Constitution. There was no reasonable suspicion that would allow a legitimate 'stop and frisk' action. The alleged waiver of rights by the accused was not done intelligently, knowingly, and without improper pressure or coercion."
• "It is the police officer who should observe facts that would lead to a reasonable degree of suspicion of a person. The police officer should not adopt the suspicion initiated by another person."
• "[While] probable cause is not required to conduct a 'stop and frisk,' it nevertheless holds that mere suspicion or a hunch will not validate a 'stop and frisk.' A genuine reason must exist, in light of the police officer's experience and surrounding conditions, to warrant the belief that the person detained has weapons concealed about him."
• "Appellant's silence should not be lightly taken as consent to such search. The implied acquiescence to the search, if there was any, could not have been more than mere passive conformity given under intimidating or coercive circumstances and is thus considered no consent at all within the purview of the constitutional guarantee."
• "Any evidence obtained in violation of [the right against unreasonable searches and seizures] shall be inadmissible for any purpose in any proceeding."
• "Evidence obtained through unlawful seizures should be excluded as evidence because it is 'the only practical means of enforcing the constitutional injunction against unreasonable searches and seizures.'"

• Posadas v. Court of Appeals (1990): Cited as an early case adopting "stop and frisk" in the Philippines, where suspicious circumstances (acting suspiciously, fleeing) were deemed akin to probable cause for inspection. Distinguished because Cogaed showed no suspicious behaviour.
• Malacat v. Court of Appeals (1997): Cited extensively to clarify that "stop and frisk" requires a "genuine reason" based on the officer's experience and observation, not mere suspicion or hunch, and primarily serves safety/weapon detection. Used to emphasize the lack of genuine reason in Cogaed's case.
• Manalili v. Court of Appeals (1997): Cited as an example where police observation of physical signs (reddish eyes, swaying walk, avoidance) constituted sufficient facts for a valid stop and investigation related to drug use. Contrasted with Cogaed's situation where no such signs were observed by the police.
• People v. Solayao (1996): Cited as another example of a valid stop and search where suspicious circumstances (appearing drunk, wearing camouflage, fleeing) justified police action. Contrasted with Cogaed's lack of suspicious actions.
• Esquillo v. People (2010): Cited Justice Bersamin's dissent emphasizing that reliance on a single suspicious circumstance is insufficient for a reasonable search; multiple activities are needed to warrant an inference of criminality. Applied to argue that even if Cogaed admitted carrying the bag for Marvin, it was only one circumstance.
• People v. Aruta (1998): Cited as factually analogous. Police acted on an informant's tip about "Aling Rosa" transporting drugs via bus. The Court found the search illegal as there were no suspicious circumstances preceding the arrest, which was prompted solely by the informant. Cogaed's case was deemed almost identical.
• People v. Aminnudin (1988): Cited as similar to Aruta and Cogaed. NBI acted on a tip, waited for the named suspect to disembark, and searched his bag, finding drugs. The Court ruled the search illegal for lack of suspicious circumstances observed by officers.
• People v. Chua (2003): Cited as another case with similar facts where police acted on information about a drug dealer, conducted a stakeout, and apprehended the accused upon arrival based solely on the informant's identification. The search was ruled an invalid 'stop-and-frisk'. Also cited for the two elements required for an in flagrante delicto arrest, both found missing in Cogaed's apprehension.
• Stonehill v. Diokno (1967): Cited as the origin of the exclusionary rule in Philippine jurisprudence, prohibiting general warrants and excluding illegally seized evidence.

• Constitution, Article III, Section 2: (Right against unreasonable searches and seizures) - The core provision violated.
• Constitution, Article III, Section 3(2): (Exclusionary Rule) - The basis for declaring the seized marijuana inadmissible.
• Rules of Court, Rule 113, Section 5: (Arrest without warrant; when lawful) - Used to determine that Cogaed's warrantless arrest was unlawful as none of the grounds (in flagrante delicto, hot pursuit, escapee) were present.
• Rules of Court, Rule 126, Section 13: (Search incident to lawful arrest) - Found inapplicable because the prerequisite lawful arrest was absent.
• Republic Act No. 9165 (Comprehensive Dangerous Drugs Act of 2002), Section 11: (Possession of Dangerous Drugs) - The provision under which Cogaed was charged.
• Republic Act No. 9165, Section 21: (Custody and Disposition of Confiscated, Seized, and/or Surrendered Dangerous Drugs...) - Mentioned as the basis for one of the appellant's arguments (chain of custody), but deemed unnecessary to discuss by the Court due to the ruling on the illegal search.
• Republic Act No. 9344 (Juvenile Justice and Welfare Act of 2006): The basis for dismissing the case against Cogaed's 14-year-old companion, Santiago Dayao.