The Comprehensive Dangerous Act of 2002 also known as RA 9165 repealed RA no. 6425. It was signed onto law by then President macapagal-Arroyo on June 7, 2002 and took effect on July 4, 2002.
Below are some of the Supreme Court Decisions applying and/or interpreting the provisions of RA 9165.
Asiatico vs. People (GR 195005)
For illegal possession of regulated or prohibited drugs, the prosecution must establish the following elements:
(1) the accused is in possession of an item or object, which is identified to be a prohibited or regulated drug;
(2) such possession is not authorized by law; and
(3) the accused freely and consciously possessed the drug.
All these elements were duly established by the prosecution. Rosana was found to have in her possession 0.05 gram of shabu. There was nothing in the records showing that she had authority to possess it. Jurisprudence also teaches Us that mere possession of a prohibited drug constitutes prima facie evidence of knowledge or animus possidendi sufficient to convict an accused in the absence of any satisfactory explanation. Rosana also failed to present contrary evidence to rebut her possession of the shabu.
People of the Phils. vs. Umipang (GR 190321)
Minor deviations from the procedures under R.A. 9165 would not automatically exonerate an accused from the crimes of which he or she was convicted. This is especially true when the lapses in procedure were recognized and explained in terms of  justifiable grounds. There must also be a showing that the police officers intended to comply with the procedure but were thwarted by some justifiable consideration/reason.
However, when there is gross disregard of the procedural safeguards prescribed in the substantive law (R.A. 9165), serious uncertainty is generated about the identity of the seized items that the prosecution presented in evidence. This uncertainty cannot be remedied by simply invoking the presumption of regularity in the performance of official duties, for a gross, systematic, or deliberate disregard of the procedural safeguards effectively produces an irregularity in the performance of official duties. As a result, the prosecution is deemed to have failed to fully establish the elements of the crimes charged, creating reasonable doubt on the criminal liability of the accused.
For the arresting officers failure to adduce justifiable grounds, we are led to conclude from the totality of the procedural lapses committed in this case that the arresting officers deliberately disregarded the legal safeguards under R.A. 9165. These lapses effectively produced serious doubts on the integrity and identity of the corpus delicti, especially in the face of allegations of frame-up. Thus, for the foregoing reasons, we must resolve the doubt in favor of accused-appellant, as every fact necessary to constitute the crime must be established by proof beyond reasonable doubt.
Pimentel vs. Comelec (GR 161658)
In essence, Pimentel claims that Sec. 36(g) of RA 9165 and COMELEC Resolution No. 6486 illegally impose an additional qualification on candidates for senator. He points out that, subject to the provisions on nuisance candidates, a candidate for senator needs only to meet the qualifications laid down in Sec. 3, Art. VI of the Constitution, to wit: (1) citizenship, (2) voter registration, (3) literacy, (4) age, and (5) residency. Beyond these stated qualification requirements, candidates for senator need not possess any other qualification to run for senator and be voted upon and elected as member of the Senate. The Congress cannot validly amend or otherwise modify these qualification standards, as it cannot disregard, evade, or weaken the force of a constitutional mandate, or alter or enlarge the Constitution.
Pimentels contention is well-taken. Accordingly, Sec. 36(g) of RA 9165 should be, as it is hereby declared as, unconstitutional. It is basic that if a law or an administrative rule violates any norm of the Constitution, that issuance is null and void and has no effect. The Constitution is the basic law to which all laws must conform; no act shall be valid if it conflicts with the Constitution. In the discharge of their defined functions, the three departments of government have no choice but to yield obedience to the commands of the Constitution. Whatever limits it imposes must be observed.
SJS vs. DDB, PDEA (GR 157870)
Taking into account the foregoing factors, i.e., the reduced expectation of privacy on the part of the employees, the compelling state concern likely to be met by the search, and the well-defined limits set forth in the law to properly guide authorities in the conduct of the random testing, we hold that the challenged drug test requirement is, under the limited context of the case, reasonable and, ergo, constitutional.
Like their counterparts in the private sector, government officials and employees also labor under reasonable supervision and restrictions imposed by the Civil Service law and other laws on public officers, all enacted to promote a high standard of ethics in the public service. And if RA 9165 passes the norm of reasonableness for private employees, the more reason that it should pass the test for civil servants, who, by constitutional command, are required to be accountable at all times to the people and to serve them with utmost responsibility and efficiency.
We find the situation entirely different in the case of persons charged before the public prosecutors office with criminal offenses punishable with six (6) years and one (1) day imprisonment. The operative concepts in the mandatory drug testing are randomness and suspicionless. In the case of persons charged with a crime before the prosecutors office, a mandatory drug testing can never be random or suspicionless. The ideas of randomness and being suspicionless are antithetical to their being made defendants in a criminal complaint. They are not randomly picked; neither are they beyond suspicion.
When persons suspected of committing a crime are charged, they are singled out and are impleaded against their will. The persons thus charged, by the bare fact of being haled before the prosecutors office and peaceably submitting themselves to drug testing, if that be the case, do not necessarily consent to the procedure, let alone waive their right to privacy. To impose mandatory drug testing on the accused is a blatant attempt to harness a medical test as a tool for criminal prosecution, contrary to the stated objectives of RA 9165. Drug testing in this case would violate a persons right to privacy guaranteed under Sec. 2, Art. III of the Constitution. Worse still, the accused persons are veritably forced to incriminate themselves.
People vs. Fundales, Jr. (GR 184606)
Section 86 of RA No. 9165 deals with inter-agency relations of the PNP and other law enforcement agencies with the PDEA. It is an administrative provision designating the PDEA as the lead agency in dangerous drugs cases. We have already ruled that nothing in RA No. 9165 suggests that it is the intention of the legislature to make an arrest in drugs cases illegal if made without the participation of the PDEA. In the implementing rules and regulations of RA No. 9165, Section 86(a) clearly states:
“(a) Relationship/Coordination between the PDEA and Other Agencies. – The PDEA shall be the lead agency in the enforcement of the Act, while the PNP, the NBI and other law enforcement agencies shall continue to conduct anti-drug operations in support of the PDEA xxx Provided, finally, that nothing in this IRR shall deprive the PNP, the NBI, other law enforcement personnel and the personnel of the Armed Forces of the Philippines (AFP) from effecting lawful arrests and seizures in consonance with the provisions of Section 5, Rule 113 of the Rules of Court.”
Suffice it to state that in this case, the danger of abuse that the provision seeks to prevent is not present. We therefore see no reason why the non-participation of the PDEA would render the arrest illegal and the evidence obtained therein inadmissible considering that the integrity and evidentiary value of the seized prohibited substances and dangerous drugs have been properly preserved.