1 

IN THE 

SUPREME COURT OF THE STATE OF ARIZONA

STATE OF ARIZONA, EX REL. WILLIAM G. MONTGOMERY, MARICOPA 

COUNTY ATTORNEY, 

Petitioner 

v. 

THE HONORABLE MYRA HARRIS, COMMISSIONER OF THE SUPERIOR COURT 

OF THE STATE OF ARIZONA, IN AND FOR THE COUNTY OF MARICOPA, 

Respondent Commissioner 

HRACH SHILGEVORKYAN, 

Real Party in Interest 

No. CV-13-0056-PR 

Filed April 22, 2014 

Appeal from the Arcadia Biltmore Justice Court 

The Honorable David Fletcher, Judge Pro Tempore 

No. TR 2011-100433 

AFFIRMED 

Appeal from the Superior Court in Maricopa County 

The Honorable Myra Harris, Commissioner 

No. LC 2011-100433-001 

AFFIRMED 

Opinion of the Court of Appeals, Division One 

232 Ariz. 76, 301 P.3d 580 (2013) 

VACATED 

COUNSEL: 

William G. Montgomery, Maricopa County Attorney, Andrea L. Kever, 

Deputy County Attorney, Susan L. Luder, Deputy County Attorney 

(argued), Phoenix, for State of Arizona 

Clark L. Derrick, Rhonda E. Neff, Kimerer & Derrick, P.C., Phoenix; and 

Michael Alarid, III (argued), Law Offices of David Michael Cantor, P.C., 

Phoenix, for Hrach Shilgevorkyan 
STATE V. HARRIS (SHILGEVORKYAN) 

Opinion of the Court 

2 

Stephen Paul Barnard, Law Offices of Stephen Paul Barnard P.C., Tucson; 

Joe St. Louis, Nesci & St. Louis, PLLC, Tucson; and Lawrence S. Koplow, 

Ridenour Hienton & Lewis, PLLC, Phoenix, for Amicus Curiae Arizona 

Attorneys for Criminal Justice 

Jon Eliason, Mesa City Prosecutor, Molly Lynch, Assistant City 

Prosecutor, Mesa, for Amicus Curiae Mesa City Prosecutor’s Office 

JUSTICE BRUTINEL authored the opinion of the Court, in which CHIEF

JUSTICE BERCH, VICE CHIEF JUSTICE BALES and JUSTICE PELANDER

joined, and JUSTICE TIMMER dissented. 

JUSTICE BRUTINEL, opinion of the Court: 

¶1 Arizona Revised Statutes § 28-1381(A)(3) makes it unlawful 

for a driver to be in actual physical control of a vehicle if there is “any 

drug defined in [A.R.S.] § 13-3401 or its metabolite in the person’s body.” 

We are asked to determine whether the phrase “its metabolite” includes 

Carboxy-Tetrahydrocannabinol (“Carboxy-THC”), a non-impairing 

metabolite of Cannabis,1 a proscribed drug listed in § 13-3401. We 

conclude that it does not. 

I. 

¶2 Police stopped a vehicle driven by Hrach Shilgevorkyan for 

speeding and making unsafe lane changes. Suspecting that he was 

impaired, officers administered field sobriety tests. After participating in 

the tests, Shilgevorkyan admitted that he had smoked some “weed” the 

night before and voluntarily submitted to a blood test that revealed 

Carboxy-THC in his blood. 

¶3 The State charged Shilgevorkyan with two counts of driving 

under the influence. Count one alleged a violation of A.R.S. § 28-

1381(A)(1) (“the (A)(1) charge”), which prohibits a person from driving a 

vehicle in Arizona “[w]hile under the influence of . . . any drug . . . if the 

person is impaired to the slightest degree.” Count two alleged a violation 

 

1 Cannabis is commonly referred to as marijuana and as defined in 

A.R.S. § 13-3401(4)(b) includes tetrahydrocannabinol (“THC”), its primary 

psychoactive component. 
STATE V. HARRIS (SHILGEVORKYAN) 

Opinion of the Court 

3 

of A.R.S. § 28-1381(A)(3) (“the (A)(3) charge”), which prohibits driving a 

vehicle “[w]hile there is any drug defined in § 13-3401 or its metabolite in 

the person’s body.” 

¶4 Shilgevorkyan moved to dismiss the (A)(3) charge, arguing 

that the blood test revealed neither the presence of THC nor “its 

metabolite” Hydroxy-Tetrahydrocannabinol (“Hydroxy-THC”). At an 

evidentiary hearing, the State presented expert witness testimony that: (1) 

marijuana has “many, many metabolites,” (2) Hydroxy-THC and 

Carboxy-THC are the two major marijuana metabolites, (3) although it is 

possible to test for Hydroxy-THC in the blood, the Arizona Department of 

Public Safety chooses not to do so because Hydroxy-THC does not “exist 

in the blood for very long” and is quickly converted to Carboxy-THC, (4) 

Carboxy-THC is inactive and does not cause impairment, and (5) 

Carboxy-THC can remain in a person’s body for as many as twenty-eight 

to thirty days after the ingestion of marijuana. 

¶5 At the conclusion of the hearing, the justice court dismissed 

the (A)(3) charge, and the State voluntarily dismissed the (A)(1) charge. 

The State appealed to the superior court, which affirmed. That court 

reasoned that the word “metabolite” in § 28-1381(A)(3) is ambiguous 

because it is unclear whether it should be read as singular or plural. 

Although the court acknowledged that Carboxy-THC is a marijuana 

metabolite, it was unconvinced that the legislature intended to include all 

possible byproducts — particularly those that are inactive and cannot 

impair the driver. 

¶6 The State then filed a petition for special action with the 

court of appeals, which accepted jurisdiction and granted relief. State ex 

rel. Montgomery v. Harris ex rel. Cnty. of Maricopa, 232 Ariz. 76, 301 P.3d 580 

(App. 2013). The court held that “§ 28-1381(A)(3)’s language prohibiting 

driving with a proscribed drug or ‘its metabolite’ includes the metabolite 

Carboxy-THC,” id. ¶ 14, based on the reasoning in State v. Hammonds, 192 

Ariz. 528, 968 P.2d 601 (App. 1998), and State v. Phillips, 178 Ariz. 368, 873 

P.2d 706 (App. 1994). The court in Hammonds held that the (A)(3) offense 

was not “irrationally overinclusive,” 192 Ariz. at 530, 968 P.2d at 603, and 

the court in Phillips determined that it was not unconstitutionally vague or 

overbroad, 178 Ariz. at 370, 873 P.2d at 708. The court of appeals noted 

that although neither case considered the meaning of “metabolite,” they 

demonstrated that A.R.S. § 28-1381(A)(3) “must be interpreted broadly to 
STATE V. HARRIS (SHILGEVORKYAN) 

Opinion of the Court 

4 

appropriately effectuate the legislative purpose and intent underpinning 

the statutory language.” Montgomery, 232 Ariz. at 79 ¶ 14, 301 P.3d at 583. 

¶7 We granted review because whether § 28-1381(A)(3) applies 

to non-impairing metabolites presents a recurring issue of statewide 

importance. We have jurisdiction under Article 6, Section 5(3) of the 

Arizona Constitution and A.R.S. § 12-120.24. 

II. 

A.

¶8 We review questions of statutory interpretation de novo. 

State v. Hansen, 215 Ariz. 287, 289 ¶ 6, 160 P.3d 166, 168 (2007). When 

interpreting a statute, our goal is to “fulfill the intent of the legislature that 

wrote it.” Bilke v. State, 206 Ariz. 462, 464 ¶ 11, 80 P.3d 269, 271 (2003). 

“[T]he best and most reliable index of a statute’s meaning is its language 

and, when the language is clear and unequivocal, it is determinative of the 

statute’s construction.” Hansen, 215 Ariz. at 289 ¶ 7, 160 P.3d at 168. 

¶9 The term “metabolite” is not defined by statute. When 

statutory terms are undefined, courts may reference dictionaries. State v. 

Wise, 137 Ariz. 468, 470 n.3, 671 P.2d 909, 911 n.3 (1983); see Baker v. Univ. 

Physicians Healthcare, 231 Ariz. 379, 384 ¶ 15, 296 P.3d 42, 47 (2013). A 

standard medical dictionary defines metabolite as “[a]ny product of 

metabolism.” Taber’s Cyclopedic Medical Dictionary 1349 (20th ed. 2005). 

It defines metabolism in pertinent part, as “the sum of all physical and 

chemical changes that take place within an organism.” Id. These 

definitions comport with the State’s expert’s testimony, which defined 

“metabolite” as “any chemical compound that is produced during the 

process of metabolism, the breakdown process of getting rid of a drug or 

substance.” 

¶10 Shilgevorkyan argues that the meaning of “its metabolite” in 

§ 28-1381(A)(3) is clear. He asserts that because the statute uses the 

possessive singular, it prohibits only Hydroxy-THC, the initial product of 

the metabolism of THC. Labeling Hydroxy-THC the “primary” 

metabolite, he contends the statute does not include the products of the 

further breakdown of Hydroxy-THC into subsequent or “secondary” 

metabolites such as Carboxy-THC. He further argues that interpreting 
STATE V. HARRIS (SHILGEVORKYAN) 

Opinion of the Court 

5 

“metabolite” in the plural expands the statutory definition to include a 

“secondary non-psychoactive metabolite . . . [that] does not cause 

impairment,” which is inconsistent with the legislature’s intent to 

criminalize driving under the influence of an intoxicating substance. The 

State, on the other hand, argues we should construe “metabolite” in the 

plural in accordance with A.R.S. § 1-214(B), which generally provides that 

statutory “[w]ords in the singular . . . include the plural . . . .” 

¶11 There is more than one plausible meaning for the phrase “its 

metabolite,” whether read as singular or plural. The argument that “its 

metabolite,” although phrased in the singular, includes all of a proscribed 

drug’s byproducts is reasonable based on § 1-214(B). Conversely, the 

argument that the statutory language reflects the legislature’s intent to 

only penalize drivers with primary or impairment-causing metabolites in 

their system is equally reasonable. Additionally, even if read in the plural, 

“metabolites” could reasonably mean multiple primary metabolites for 

drugs having more than one rather than both primary and secondary 

metabolites. 

¶12 Because the term “its metabolite” is reasonably susceptible 

to differing interpretations, the statute is ambiguous and we cannot 

determine from the term alone whether the legislature intended to 

penalize the presence of any byproduct, including Carboxy-THC, in a 

driver’s blood. See Arizona Citizens Clean Elections Com’n v. Brain, CV-13-

0341-PR, 2014 WL 1307659, at *4 ¶ 13 (Ariz. Apr. 2, 2014); see also Joshua C. 

Snow, The Unconstitutional Prosecution of Controlled Substance Metabolites 

Under Utah Code § 41-6A-517, 2013 Utah L. Rev. OnLaw 195, 198 (2013) 

(“Although [per se DUI] statutes are purportedly designed to make 

prosecution simpler and more effective by removing the necessity to 

prove impairment or quantifiable levels of drugs in the system, the 

statutes are rife with ambiguity and complexity, which weaken their 

legitimacy and validity.”). Accordingly, we look to secondary rules of 

statutory construction to determine § 28-1381(A)(3)’s meaning. 

B. 

¶13 Statutes should be construed sensibly to avoid reaching an 

absurd conclusion. Mendelsohn v. Super. Ct. in and for Maricopa Cnty., 76 

Ariz. 163, 169, 261 P.2d 983, 987–88 (1953). When a statute’s meaning 

cannot be discerned from its language alone, “we attempt to determine 
STATE V. HARRIS (SHILGEVORKYAN) 

Opinion of the Court 

6 

legislative intent by interpreting the statute as a whole, and consider ‘the 

statute’s context, subject matter, historical background, effects and 

consequences, and spirit and purpose.’” Calik v. Kongable, 195 Ariz. 496, 

500 ¶ 16, 990 P.2d 1055, 1059 (1999) (quoting Aros v. Beneficial Arizona, Inc., 

194 Ariz. 62, 66, 977 P.2d 784, 788 (1999)). Courts also consider “the policy 

behind the statute and the evil it was designed to remedy.” State v. Korzep, 

165 Ariz. 490, 493, 799 P.2d 831, 834 (1990). Furthermore, we consider a 

statute “in light of its place in the statutory scheme,” Grant v. Bd. of Regents 

of Univ. and State Colls. of Ariz., 133 Ariz. 527, 529, 652 P.2d 1374, 1376 

(1982), and although statutory title headings are not part of the law, they 

can aid in its interpretation, State v. Barnett, 142 Ariz. 592, 597, 691 P.2d 

683, 688 (1984). 

¶14 The State’s interpretation that “its metabolite” includes any

byproduct of a drug listed in § 13-3401 found in a driver’s system leads to 

absurd results. See State v. Estrada, 201 Ariz. 247, 251 ¶ 14, 34 P.3d 356, 360 

(2001) (observing that a “result is absurd if it is so irrational, unnatural, or 

inconvenient that it cannot be supposed to have been within the intention 

of persons with ordinary intelligence and discretion”) (internal quotation 

marks omitted). 

¶15 Most notably, this interpretation would create criminal 

liability regardless of how long the metabolite remains in the driver’s 

system or whether it has any impairing effect. For example, at oral 

argument the State acknowledged that, under its reading of the statute, if 

a metabolite could be detected five years after ingesting a proscribed 

drug, a driver who tested positive for trace elements of a non-impairing 

substance could be prosecuted. 

¶16 Additionally, this interpretation would criminalize 

otherwise legal conduct. In 2010, Arizona voters passed the Arizona 

Medical Marijuana Act (“AMMA”), legalizing marijuana for medicinal 

purposes. A.R.S. § 36-2801 et seq. Despite the legality of such use, and 

because § 28-1381(A)(3) does not require the State to prove that the 

marijuana was illegally ingested, prosecutors can charge legal users under 

the (A)(3) provision. Because Carboxy-THC can remain in the body for as 

many as twenty-eight to thirty days after ingestion, the State’s position 

suggests that a medical-marijuana user could face prosecution for driving 

any time nearly a month after they had legally ingested marijuana. Such a 

prohibition would apply even when the driver had no impairing 
STATE V. HARRIS (SHILGEVORKYAN) 

Opinion of the Court 

7 

substance in his or her body and notwithstanding the State’s ability to test 

both for THC, the primary substance that causes impairment, and 

Hydroxy-THC, the metabolite capable of causing impairment. 

¶17 Finally, this interpretation would allow the prosecution of an 

individual who drives after ingesting a legal substance that shares a nonimpairing metabolite with a proscribed substance. For example, 

serotonin, a legal substance, and the proscribed drug bufotenine share a 

common metabolite, 5-hydroxindoleactic acid (“5-HIAA”).2 See 

Kärkkäinen, Jorma, et al., Urinary excretion of bufotenin (N, N -dimethyl-5-

hydroxytryptamine) is increased in suspicious violent offenders: A confirmatory 

study, 58 Psychiatry Research, 145 (1995); Moore, Todd M., et al., A metaanalysis of serotonin metabolite 5-HIAA and antisocial behavior, 28 Aggressive 

Behavior, 299 (2002). Under the State’s interpretation of “metabolite,” it 

could prosecute a driver who had 5-HIAA in his or her system after 

ingesting a legal serotonin supplement or, for that matter, whose blood 

contains 5-HIAA as a byproduct of naturally produced serotonin. Because 

§ 28-1381(A)(3) does not require the State to prove that a substance 

discovered in a driver’s body is actually metabolized from a proscribed 

drug, the State’s interpretation would permit prosecution if the discovered 

substance is a metabolite of a proscribed drug even if the proscribed drug 

was never ingested. These results are absurd and make the State’s 

argument untenable.3

 

2 Bufotenine, proscribed by A.R.S. § 13-3401(6)(a)(v), is a 

hallucinogenic drug generally ingested by licking the backs of cane toads. 

See Christen Conger, Are there really hallucinogenic frogs?, HOW STUFF 

WORKS (August 12, 2008), http://www.science. howstuffworks.com/ 

zoology/reptiles-amphibians/hallucinogenic-frog1.htm 

3 The Dissent notes that under its plain language interpretation, § 28-

1381(A)(3) might be constitutionally challenged as applied to a driver who 

had ingested a legal (or naturally occurring) substance that shares a 

metabolite with an illegal drug or who legally ingested marijuana. 

Dissent at ¶ 31. In support of this assertion the Dissent cites State v. Boyd, 

201 Ariz. 27, 29–30 ¶¶ 12–13, 31 P.3d 140, 142–43) (App. 2001), which held 

§ 28-1381(A)(3), as applied, void for vagueness, id. That § 28-1381(A)(3) is 

subject to more than one reasonable interpretation, one of which might 

render it unconstitutional, highlights its ambiguity. Furthermore, we 

“construe statutes, when possible, to avoid constitutional difficulties.” 
STATE V. HARRIS (SHILGEVORKYAN) 

Opinion of the Court 

8 

C.

¶18 The legislative history behind § 28-1381(A)(3) reflects that 

the legislature sought to prevent impaired driving. The statute was added 

in 1990 by House Bill (“H.B.”) 2433. A Senate fact sheet explained that 

H.B. 2433’s purpose was to “make numerous substantive and conforming 

changes to the provisions relating to the offense of driving under the 

influence of liquor or drugs.” STAFF OF ARIZ. S., 39TH LEGIS. 2D SESSION,

H.B. 2433 FACT SHEET, at 1 (June 21, 1990). 

¶19 Section 28-1381(A)(3)’s placement within the statutory 

scheme also demonstrates a legislative intent to prevent and punish 

impaired driving, not simply driving while having a non-impairing 

metabolite in one’s system. The “its metabolite” language appears in the 

“Driving Under the Influence” section of Arizona’s statutes. A.R.S. 

Chapter 4, art. 3. And the statute’s title begins “Driving or actual physical 

control while under the influence . . . .” A.R.S. § 28-1381 (emphasis added). 

¶20 Consistent with this legislative history, the court of appeals 

has noted that “[t]he state has a compelling legitimate interest in 

protecting the public from drivers whose ability may be impaired by the 

consumption of controlled substances . . . .” Phillips, 178 Ariz. at 372, 873 

P.2d at 710. The court further explained that the (A)(3) charge was 

enacted as a part of comprehensive DUI legislation “designed to protect 

the public by ‘reducing the terrible toll of life and limb’ on our roads.” Id. 

(quoting Fuenning v. Supr. Ct. in and for Maricopa Cnty., 139 Ariz. 590, 595, 

680 P.2d 121, 126 (1983)). 

¶21 This legislative intent is further evidenced by A.R.S. § 28-

1381(A)(2), which provides that “[i]t is unlawful for a person to drive or 

be in actual physical control of a vehicle . . . [i]f the person has an alcohol 

concentration of 0.08 or more within two hours of driving or being in 

actual physical control of the vehicle . . . .” Neither the (A)(2) nor (A)(3) 

charge requires that the State prove impairment. The (A)(2) charge creates 

a per se threshold at which a driver is presumed to be under the influence. 

See State v. Cooperman, 232 Ariz. 347, 350 ¶ 10, 306 P.3d 4, 7 (2013) 

(explaining that under § 28-1381(A)(2), whether the driver was impaired 

 

State v. Gomez, 212 Ariz. 55, 60 ¶ 28, 127 P.3d 873, 878 (2006) (citing Hayes 

v. Cont’l Ins. Co., 178 Ariz. 264, 272, 872 P.2d 668, 676 (1994)). 
STATE V. HARRIS (SHILGEVORKYAN) 

Opinion of the Court 

9 

does not matter — the only pertinent questions are whether the alcohol 

concentration exceeded 0.08 and the reading was taken within two hours 

of driving or being in actual physical control of the vehicle). 

¶22 Similarly, in enacting the (A)(3) charge, the legislature 

sought to proscribe driving by those who could be impaired from the 

presence of illegal drugs in their body. However, unlike alcohol, there is 

no generally applicable concentration that can be identified as an indicator 

of impairment for illegal drugs. Phillips, 178 Ariz. at 372, 873 P.2d at 710 

(explaining that drugs’ potency cannot be accurately predicted); see also

Gary M. Reisfield et al., The Mirage of Impairing Drug Concentration 

Thresholds: A Rationale for Zero Tolerance Per Se Driving under the Influence of 

Drugs Laws, 36 J. Analytical Toxicology 353 (2012) (explaining that 

multiple phenomena make the task of establishing impairing 

concentrations impossible). The (A)(3) charge establishes that a driver 

who tests positive for any amount of an impairing drug is legally and 

irrefutably presumed to be under the influence. Although the legislature 

could rationally choose to penalize the presence of any amount of an 

impairing metabolite, we do not believe that the legislature contemplated 

penalizing the presence of a metabolite that is not impairing. 

¶23 We find that the legislature intended to prohibit driving 

with any amount of an impairing substance resulting from a drug 

proscribed in § 13-3401 in the body. The State, however, essentially 

contends that the legislature intended a law that punishes driving under the 

influence to also punish drivers who it cannot prove were under the 

influence or had any impairing substance in their system at the time of 

driving. We are not persuaded and reject the State’s argument that § 28-

1381(A)(3) “creates a flat ban on the presence of any drug or its metabolite 

in a person’s body while driving or in actual physical control of a vehicle,” 

even when the only metabolite found is not impairing. But we likewise 

reject Shilgevorkyan’s argument that “its metabolite” means only the 

primary metabolite, because there are drugs proscribed under § 13-3401 

that have multiple primary or secondary impairing metabolites. See, e.g., 

Diazepam, National Highway Traffic Safety Administration, 

http://www.nhtsa.gov/people/injury/research/job185drugs/diazepam.

htm (last visited April 2, 2014) (explaining that diazepam has multiple 

psychoactive metabolites). 
STATE V. HARRIS (SHILGEVORKYAN) 

Opinion of the Court 

10 

¶24 Because the legislature intended to prevent impaired 

driving, we hold that the “metabolite” reference in § 28-1381(A)(3) is 

limited to any of a proscribed substance’s metabolites that are capable of 

causing impairment.4 Accordingly, marijuana users violate § 28-

1381(A)(1) if they drive while “impaired to the slightest degree,” and, 

regardless of impairment, violate (A)(3) if they are discovered with any 

amount of THC or an impairing metabolite in their body. Drivers cannot 

be convicted of the (A)(3) offense based merely on the presence of a nonimpairing metabolite that may reflect the prior usage of marijuana. 

V. 

¶25 The record establishes that Carboxy-THC, the only 

metabolite found in Shilgevorkyan’s blood, does not cause impairment. 

Accordingly, we vacate the court of appeals’ opinion and affirm the trial 

court’s dismissal of the (A)(3) charge. 

 

4 In light of our holding that “its metabolite” does not include 

Carboxy-THC, we do not address Shilgevorkyan’s various constitutional 

arguments. 
STATE V. HARRIS (SHILGEVORKYAN) 

JUSTICE TIMMER, Dissenting 

11 

JUSTICE TIMMER, dissenting: 

¶26 Arizona is one of at least seven states that combats drugged 

driving with a zero-tolerance, per se ban on driving with any controlled 

substance or its metabolite in the body. Joshua C. Snow, The 

Unconstitutional Prosecution of Controlled Substance Metabolites Under Utah 

Code § 41-6A-517, 2013 Utah L. Rev. OnLaw 195, 197–98 & n.14 (2013). 

One of these states, Delaware, explicitly excludes inactive metabolites 

from its per se ban. Del. Code Ann. tit. 21, § 4177(c)(10) (West 2014). The 

Majority aligns Arizona with Delaware by construing A.R.S. § 28-

1381(A)(3) in a manner that contradicts its plain meaning. I respectfully 

dissent. 

¶27 The Majority holds that § 28-1381(A)(3) is ambiguous 

because the phrase “its metabolite” can mean all of a proscribed drug’s 

metabolites, some of its metabolites, or only those that can cause 

impairment. See Op. ¶ 11. But “metabolite” has an accepted meaning, see 

Taber’s Cyclopedic Medical Dictionary 1349 (20th ed. 2005), and nothing 

in the language of § 28-1381 suggests that the legislature intended to 

exclude certain types of metabolites from the statutory prohibition. 

Because § 28-1381(A)(3) “admits of only one meaning,” it is not 

ambiguous. See Parrot v. DaimlerChrysler Corp., 212 Ariz. 255, 257 ¶ 7, 130 

P.3d 530, 532 (2006); see also State v. Phillips, 178 Ariz. 368, 371, 873 P.2d 

706, 709 (App. 1994) (“We fail to see how section [28-1381(A)(3)] is 

ambiguous in any way. It precisely defines, in unequivocal terms, the 

type of behavior prohibited[.]”). 

¶28 I also disagree with the Majority that the legislature must 

have intended something different from what it plainly stated in § 28-

1381(A)(3) because imposing a flat ban on driving with any metabolite of 

an illegal drug in the body is absurd. See Op. ¶¶ 14–17. The legislature 

reasonably could have concluded that a zero-tolerance provision would 

most effectively enhance detection and prosecution of drugged driving. 

¶29 First, the difficulty of detecting drug impairment justifies a 

flat ban. See Phillips, 178 Ariz. at 372, 873 P.2d at 710 (noting that, unlike 

the case with alcohol impairment, “there is no useful indicator of 

impairment from . . . drugs because they are fundamentally different from 

alcohol”). For example, an expert witness in this case testified that 

Hydroxy-THC converts quickly to Carboxy-THC, which is why law 
STATE V. HARRIS (SHILGEVORKYAN) 

JUSTICE TIMMER, Dissenting 

12 

enforcement typically does not test blood for Hydroxy-THC. Thus, a 

driver with Carboxy-THC in the blood at the time of testing may or may 

not have had Hydroxy-THC in the blood while driving. The flat ban 

ensures that a driver who had an impairing substance in the body while 

driving is prosecuted even though that substance may have quickly 

metabolized into a non-impairing substance. 

¶30 Second, the flat ban permits law enforcement to detect 

drugged driving by testing urine as well as blood. “[W]hile a urine test 

detecting metabolites does not conclusively establish the presence of the 

active proscribed parent drug in the bloodstream, neither does it rule it 

out, because the metabolite and the active parent will often be present in 

the body simultaneously.” State v. Hammonds, 192 Ariz. 528, 531 ¶ 10, 968 

P.2d 601, 604 (App. 1998). Imposing a flat ban on driving with a 

metabolite of a controlled substance in the body enhances law 

enforcement’s ability to detect drugged driving. Cf. id. ¶ 11 (“In seeking 

to protect the life and health of its citizenry, the legislature cannot be 

required to forego an effective prophylactic measure simply because it 

may be somewhat imprecise.”). 

¶31 The Majority contends that a flat ban is absurd because it 

permits prosecution if the non-impairing metabolite in the driver’s body 

derives from ingesting either medically authorized marijuana or a legal 

substance that shares a metabolite with a controlled substance. See

Op. ¶¶ 16–17. These isolated examples do not make the flat ban on the 

presence in the body of hundreds of proscribed drugs or their metabolites 

absurd. Either scenario described by the Majority would unquestionably 

trigger constitutional scrutiny that might invalidate § 28-1381(A)(3) as 

applied in particular circumstances. Cf. State v. Boyd, 201 Ariz. 27, 29–30 

¶¶ 12–13, 31 P.3d 140, 142–43 (App. 2001) (holding that although “A.R.S. § 

28-1381(A)(3) is not facially vague,” applying it to a defendant who 

consumed a legal product, GBL, that metabolized into GHB, a proscribed 

substance, was unconstitutional as applied to the defendant because it 

“fail[ed] to give him adequate notice that his actions were illegal”). And § 

28-1381(A)(3) might not apply if the detected metabolites — active or 

inactive — emanated from medically authorized marijuana use. See A.R.S. 

§ 28-1381(D) (“A person using a drug as prescribed by a medical 

practitioner licensed pursuant to title 32, chapter 7, 11, 13 or 17 is not 

guilty of violating subsection A, paragraph 3 of this section.”). This case 

does not present either situation. 
STATE V. HARRIS (SHILGEVORKYAN) 

JUSTICE TIMMER, Dissenting 

13 

¶32 I share some of the Majority’s concerns about imposing a 

zero-tolerance, per se ban on driving with the presence of non-impairing 

metabolites in the body. But because § 28-1381(A)(3) clearly and 

unambiguously reflects that the legislature intended this result, it is not 

appropriate to employ secondary canons of statutory construction to find 

a different meaning. Any constitutional challenges to this provision 

should be addressed on a case-by-case basis. I would affirm the court of 

appeals’ opinion.