dissenting.
¶21 The majority concludes that the federal Controlled Substances Act (“CSA”), 21 U.S.C. §§ 801-904 (2012), expressly preempts section 14(2)(e) of article XVIII of the Colorado Constitution, which requires the immediate return of marijuana seized by state or local law enforcement officials from a patient upon the determination that the patient-was entitled to use the marijuana for medical purposes in accordance with the Colorado Constitution, as evidenced by, among other things, a decision not to prosecute, the dismissal of charges, or an acquittal.
¶22- Because I believe that the plain language of § 885(d) of the CSA, 21 U.S.C. § 885(d), immunizes federal and state officers from civil and criminal liability in the circumstances at issue here, I perceive no conflict between the CSA and section 14(2)(e) of article XVIII of the Colorado Constitution, nor do I believe that it is impossible to comply with both the CSA and the Colorado Constitution, as the majority implicitly and the People expressly contend.
¶23 Accordingly, I do not agree that the CSA preempts section 14(2)(e) of article XVIII of the Colorado Constitution, and therefore, I respectfully dissent.
I. Analysis
¶24 As an initial matter, I note that the majority,characterizes the-issue presented as *44one of express preemption. See maj. op. ¶ 20 n.2. The majority bases this view on its understanding of § 903 of the CSA, which provides, in pertinent part:
No provision of this subchapter shall be construed as indicating an intent on the part of the Congress to occupy the field in which that provision operates ... to the exclusion of any State law on the same subject matter which would otherwise be within the authority of the State, unless there is a positive conflict between -that provision of this subchapter and that State law so that the two cannot consistently stand together.
21 U.S.C. § 903 (2012).
¶25 It is not clear to me, however, that this provision is, in fact, an express preemption provision. The statute’s subject is field preemption, and the statute’s purpose appears to be to confirm that Congress does not intend to preempt the field of drug enforcement, subject to an exception for “positive conflicts.”
¶26 Accordingly, I agree with the parties that the issue before us is more properly characterized as one of conflict preemption, under which state laws are preempted either when (1) simultaneous compliance with federal and state law is impossible or (2) the challenged state law stands as an obstacle to the accomplishment and execution of Congress’s purposes and objectives. See Arizona v. United States, 567 U.S. 387, 132 S.Ct. 2492, 2501, 183 L.Ed.2d 351 (2012). And to the extent that § 903 of the CSA defines the term “positive conflict” to refer to the situation in which a federal and state law “cannot consistently stand together,” I agree with the People that this language appears to subsume both impossibility and obstacle preemption. Thus, the distinction that the majority appears to be trying to draw between express and implied preemption here, see maj. op. ¶ 20 n.2, seems to be one without a difference.
¶27 To determine whether the CSA preempts section 14(2)(e) of article XVIII of the Colorado Constitution under the foregoing principles, we must first determine what the CSA provides.
¶28 Our primary purpose in statutory construction is to ascertain and give effect to the legislature’s intent. Doubleday v. People, 2016 CO 3, ¶ 19, 364 P.3d 193, 196. We first look to the statutory language, giving words and phrases them plain and ordinary meanings. Id. We read the words and phrases of the statute in context, and we construe them according to the rules of grammar and common usage. Id.
¶29 In addition, we must interpret a statute so as to effectuate the purpose of the legislative scheme. Id. at ¶ 20, 364 P.3d at 196. In doing so, we read the scheme as a whole, and we give consistent, harmonious, and sensible effect to all of its parts. Id. We also must avoid constructions that would render any statutory word or phrase superfluous or that would lead to illogical or absurd results. Id. If the statute is unambiguous, then we need not conduct any further statutory analysis. Id.
¶30 Here, I believe that § 885(d) of the CSA is unambiguous. That section provides:
Except as provided in sections 2234 and 2235 of Title 18, no civil or criminal liability shall be imposed by virtue of this subchap-ter upon any duly authorized Federal officer lawfully engaged in the enforcement of this subchapter, or upon any duly authorized officer of any State, territory, political subdivision thereof, the District of Columbia, or any possession of the United States, who shall be lawfully engaged in the enforcement of any law or municipal ordinance relating to controlled substances.
21 U.S.C. § 885(d) (emphasis added).
¶31 “Lawfully engaged” plainly means taking part in, pursuant to and within the scope of one’s legitimate authority. See Engage, Webster’s Third New International Dictionary (2002) (defining “engage” as, among other things, “to employ or involve oneself’ or “to take part: PARTICIPATE”). Thus, a police officer who sells drugs to a target as part of an undercover sting is lawfully engaged in performing his or her duties. A police officer who sells drugs while off duty to supplement his or her income is not lawfully engaged in performing his or her duties. See United States v. Wright, No. 06-150-JVP-CN, 2008 WL 4298570, at *3 (M.D. La. *45Sept. 16, 2008) (“[A]n officer cannot be lawfully engaged in law enforcement if he violates federal law in the course of committing an act outside the scope of his authority.”), aff'd, 634 F.3d 770 (5th Cir. 2011); S.E. v. State, 744 N.E.2d 536, 542 (Ind. Ct. App. 2001) (“Because the deputies were acting beyond the scope of their duties, they were not lawfully engaged in the execution of their duties when they helped [the juvenile defendant’s stepmother] gain access to [the defendant’s] house.... ”).
¶32 “Enforcing,” in turn, means “giving force to.” See Enforce, Webster’s Third New International Dictionary (defining “enforce” as, among other things, “to give force to”); see also United States v. Rosenthal, 454 F.3d 943, 948 (9th Cir. 2006) (noting that in returning seized marijuana to an individual pursuant to a state law mandating the return of such marijuana, the officers were “enforcing” that state law).
¶33 And “any law or municipal ordinance relating to controlled substances” assuredly includes section 14(2)(e) of article XVIII of the Colorado Constitution.
¶34 Applying these definitions here, I believe that in returning Crouse’s medical marijuana pursuant to section 14(2)(e) of article XVIII of the Colorado Constitution, the state officers would be acting within the scope of them legitimate authority (indeed, pursuant to a court order) and would unquestionably be giving force to section 14(2)(e). Accordingly, in my view, in carrying out the district court’s order, the officers would be lawfully engaged in enforcing a law relating to controlled substances pursuant to § 885(d) of the CSA.
¶35 For these reasons, I agree with the division’s conclusion that § 885(d) of the CSA would immunize the officers’ conduct. See Crouse, ¶¶ 32-38; see also State v. Okun, 231 Ariz. 462, 296 P.3d 998, 1001-02 (App. 2013) (concluding that 21 U.S.C. § 885(d) immunizes law enforcement officers from any would-be federal prosecution for complying with a court order to return the defendant’s marijuana to her); City of Garden Grove v. Superior Court, 157 Cal.App.4th 355, 68 Cal.Rptr.3d 656, 681 (2007) (same); State v. Kama, 178 Or.App. 561, 39 P.3d 866, 868 (2002) (same).
¶36 For two reasons, I am not persuaded otherwise by the majority’s determination that because section 14(2)(e) of article XVIII of the Colorado Constitution is unlawful under federal law, law enforcement officers complying with that provision cannot be said to be acting lawfully. See maj. op. ¶¶ 16-19.
¶37 First, in making this determination, the majority simply assumes its conclusion, namely, that section 14(2)(e) is preempted. This analysis strikes me as backwards. Specifically, in my view, we must first determine what “lawfully engaged” means because, as I explain more fully below, the definition of that phrase necessarily informs the preemption analysis.
¶38 Second, the majority’s analysis leads to absurd results. The majority defines “lawful” with reference to the CSA’s prohibition on distribution of controlled substances and states that when law enforcement officers return marijuana in compliance with section 14(2)(e) of article XVIII of the Colorado Constitution, they are distributing marijuana in violation of the CSA. Maj. op. ¶ 15. Under this same reasoning, however, when a law enforcement officer provides marijuana to a target in a sting operation, the officer is also distributing marijuana in violation of the CSA, clearly an absurd result.1
¶39 Perhaps having anticipated the flaws in the analysis that the majority ultimately adopts, the People advance a somewhat different argument, namely, that “lawfully engaged” requires the officers to carry out the purposes of the CSA. For several reasons, however, this argument, too, is unpersuasive.
¶40 First, for the reasons set forth above, the plain meaning of the term “lawfully engaged” does not support this interpretation. *46Nor does the plain language of § 885(d), which makes no reference to any purpose of the CSA.
¶41 Second, the People’s interpretation defines the CSA’s purpose by referring to the CSA provisions precluding the distribution of controlled substances. In doing so, however, the People overlook the fact that § 885(d), which allows the “distribution” of controlled substances in certain circumstances, is also part of the CSA and thus must be considered in determining the CSA’s purposes. In my view, doing so reveals not only an intention to prohibit the distribution of controlled substances but also an intention to allow officers to act to enforce both the CSA and, as pertinent here, any law relating to controlled substances. See 21 U.S.C. § 885(d).
¶42 I likewise am unpersuaded by the People’s argument that “enforcement” within the meaning of § 885(d) means compelling someone to comply with the law. Although in certain circumstances, “enforcement” can involve compulsion, I do not believe that it must do so or that “compulsion” captures the plain and ordinary meaning of the term “enforcement.”
¶43 Having thus concluded that § 885(d) would immunize state officers who are ordered to return Crouse’s medical marijuana to him pursuant to the Colorado Constitution, the question remains whether, in light of that conclusion, the CSA preempts section 14(2)(e) of article XVIII of the Colorado Constitution. Unlike the majority, I would conclude that it does not.
¶44 By immunizing state officers from criminal and civil liability in the circumstances at issue here, § 885(d) of the CSA effectively sanctions the return of medical marijuana pursuant to state law. Accordingly, the CSA and section 14(2)(e) of article XVIII of the Colorado Constitution can consistently stand together, and the simultaneous compliance with both is not at all impossible.
¶45 For the same reason, I fail 'to see how the return of Crouse’s medical marijuana pursuant to both the Colorado Constitution and an enforceable state court order would in any way pose an obstacle to the accomplishment and execution of the purposes and objectives of the CSA. As noted above, the CSA effectively allows the return of Crouse’s medical marijuana through its grant of immunity to state officers. Accordingly, returning such marijuana is consistent with the CSA. Moreover, I do not perceive how the return of Crouse’s medical marijuana in the limited and seemingly unusual circumstances at issue here would materially hinder the federal government’s enforcement of any applicable federal drug laws. Cf. City of Garden Grove, 68 Cal.Rptr.3d at 676 (“It is even more unreasonable to believe returning marijuana to qualified patients who have had it seized by local police will hinder the federal government’s enforcement efforts. Practically speaking, this subset of medical marijuana users is too small to make a measurable impact on the war on drugs. Not only are their numbers meager, persons seeking the return of their medical marijuana are not entitled to possess the drug in such quantities as would make them likely candidates for federal prosecution. Upholding the return of [the medical marijuana patient’s] 8.1 grams of marijuana would simply not constitute a real or meaningful threat to the federal drug enforcement effort. This is not a case in which preemption is necessary to the federal scheme.”).
II. Conclusion
¶46 For these reasons, I would affirm the judgment of the court of appeals. Accordingly, I respectfully dissent.
I am authorized to state that CHIEF JUSTICE RICE and JUSTICE HOOD join in this dissent.
. Nor could the majority save its flawed analysis were it to define "lawfully engaged” as (1) “compliant with federal law” when discussing the return provision but (2) “operating to advance proper law enforcement purposes" when considering officers involved in sting operations. The phrase must be defined consistently for all purposes, and my definition, which reflects the phrase’s plain and ordinary meaning, does so.