Can Police Search a Car for the Smell of Weed in Arizona? Not Even Suspicion

Arizona’s voters put the odor rule in the statute when they legalized in 2020 — and they wrote a DUI exception into the same subsection. The case law hasn’t caught up.

Can Police Search a Car for the Smell of Weed in Arizona? Not Even Suspicion — Unless It’s DUI

Not on odor alone for a crime. A.R.S. § 36-2852(C): the odor of marijuana or burnt marijuana “does not by itself constitute reasonable articulable suspicion of a crime.” The exception is written into the statute: (C) does not apply when you are investigating DUI under § 28-1381.

Arizona: odor and the car — Odor alone isn't reasonable suspicion of a crime — unless you're working a DUI. — Arizona: odor and the car — the statute, the controlling cases, and what still gets you into the car. The full breakdown lives inside StreetSense, offline.

What § 36-2852 says

(C): “Notwithstanding any other law, the odor of marijuana or burnt marijuana does not by itself constitute reasonable articulable suspicion of a crime. This subsection does not apply when a law enforcement officer is investigating whether a person has violated section 28-1381.”
(A): lawful adult conduct — including possessing and transporting one ounce or less — “may not constitute the basis for detention, search or arrest.”
Read (C) exactly. It speaks to reasonable suspicion “of a crime.” It does not use the words probable cause or search. No published Arizona appellate decision since Prop 207 has decided whether odor alone is probable cause to search a car.

The DUI exception

When you are investigating a § 28-1381 DUI, (C) steps aside. The statute doesn’t say what the odor then proves; it only removes the bar.
The marijuana DUI still needs impairment. § 36-2852(B): a person with marijuana metabolites or components in the body violates § 28-1381(A)(3) “only if the person is also impaired to the slightest degree.” DUI is a class 1 misdemeanor.
So develop impairment — driving, observations, testing — and write it down. The odor is part of a DUI investigation. It is not a shortcut around one.

The old rule: Sisco and Cheatham

State v. Sisco, 239 Ariz. 532 (2016), and State v. Cheatham, 240 Ariz. 1 (2016), both unanimous Arizona Supreme Court decisions, held that the smell of marijuana alone was probable cause — unless other facts suggested medical-marijuana-compliant use. Cheatham applied that to burnt marijuana from a car.
Those are pre-Prop 207 cases, decided when marijuana was generally illegal and only medical use was allowed. Sisco itself said that if Arizona “eventually decriminalizes marijuana, our analysis and conclusion in this context might well be different.”
They have not been expressly overruled, and no published appellate decision has applied or rejected them since Prop 207. Don’t write a report that relies on them.

How much is legal

Adults 21 and over may possess and transport one ounce or less, no more than 5 grams of it concentrate (§ 36-2852(A)(1)).
More than one ounce up to 2.5 ounces (no more than 12.5 grams concentrate): a petty offense, not a felony (§ 36-2853(A)). The class 6 felony in § 13-3405 starts above that.
Under 21 with one ounce or less: civil penalty up to $100 for a first violation, a petty offense for a second, a class 1 misdemeanor for a third (§ 36-2853(B)). Smoking in a public place: petty offense.
In the car: the chapter doesn’t allow consuming marijuana while driving or riding in the passenger seat or compartment of an operating vehicle (§ 36-2851(8)(b)). It states no penalty of its own, and we found no Arizona marijuana open-container statute.

The federal floor — and why it doesn't decide your case

Under the Fourth Amendment the automobile exception needs probable cause and nothing more (Maryland v. Dyson, 527 U.S. 465 (1999)), and marijuana is still illegal under federal law.
Arizona’s rule comes from its statute, which gives more protection than that floor.
That is the floor. A state court applying its own statute or constitution can — and here does — suppress what a federal court would admit. Work to your state’s rule.

How it plays out on the street

Evening stop for an expired plate. Heavy smell of burnt marijuana. The driver is steady, eyes clear, speech normal. The odor doesn’t give you reasonable suspicion of a crime, and one ounce or less in the car isn’t a basis to detain or search. Now change one fact: the car was weaving and the driver’s reactions are slow. You’re investigating a § 28-1381 DUI, and (C) no longer bars the odor. Run the DUI investigation, document the impairment, and let the evidence of impairment carry the arrest.

Frequently asked questions

Can police search your car for the smell of weed in Arizona?

Arizona’s statute says the odor of marijuana or burnt marijuana does not by itself constitute reasonable articulable suspicion of a crime (A.R.S. § 36-2852(C)), and lawful adult possession may not be the basis for detention, search or arrest. The exception is a DUI investigation under § 28-1381. No published Arizona appellate decision since Prop 207 has decided whether odor alone is probable cause to search a vehicle.

Is weed odor probable cause in Arizona?

The 2016 Arizona Supreme Court cases that treated odor alone as probable cause, State v. Sisco and State v. Cheatham, were decided before Prop 207 legalized adult use. Since then the statute bars odor alone as reasonable suspicion of a crime outside DUI investigations, and no published appellate decision has resolved the probable-cause question.

How much weed can you have in Arizona?

Adults 21 and over may possess up to one ounce, with no more than 5 grams of concentrate. More than one ounce and up to 2.5 ounces is a petty offense under A.R.S. § 36-2853(A).

Carry the rule, not the guesswork. StreetSense breaks down Arizona law like this — the statute, the limit, and the charge that actually sticks — verified against the code and available fully offline on shift. Start the free trial.

StreetSense is an educational reference for law enforcement, not legal advice. State law changes, and your department policy may be stricter than the statute. Always follow your state’s current rule and your agency’s policy.

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