State of Arizona v. Francisco Flores Huez, Jr., 240 Ariz. 406

In March 2015 a Tucson officer observed Francisco Florez Huez Jr. riding a bicycle on an unimproved dirt/gravel strip between curb and property line and stopped him for alleged traffic violations.
Officer cited Huez for riding on the sidewalk and for riding on the left/wrong side of the roadway; during the stop officers discovered outstanding warrants and arrested Huez; a search incident to arrest produced marijuana.
At the suppression hearing the officer conceded there was no actual paved sidewalk and that Huez was riding in an unpaved, unimproved area; the state conceded Huez was not engaging in illegal behavior at the time of the stop.
The trial court denied the motion to suppress, relying in part on Heien (reasonable-mistake-of-law doctrine) and found the stop objectively reasonable.
On appeal the court examined (1) whether the officer had reasonable suspicion to stop Huez, (2) whether any mistake of law was objectively reasonable under Heien, and (3) whether the discovery of the warrant/arrest attenuated the taint of an unlawful stop (Brown/Strieff analysis).
The Court of Appeals held the officer lacked reasonable suspicion and any claimed mistake of law was not objectively reasonable, but remanded for an evidentiary hearing limited to the State’s attenuation argument because the State had not developed the record below on that issue.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Legality of stop / reasonable suspicion	Officer had reasonable suspicion Huez violated Tucson Code §5‑2 (sidewalk) or ARS §28‑815 (bicyclist not keeping right on roadway)	Huez rode in an unimproved dirt area (not a sidewalk or roadway); no traffic violation occurred, so no reasonable suspicion	Stop was unlawful: facts showed Huez was not on a roadway or a defined sidewalk, so no particularized reasonable suspicion existed
Reasonable mistake of law (Heien)	Any mistake construing the dirt strip as a sidewalk/roadway was objectively reasonable	Code definitions are unambiguous; officer’s construction was unreasonable	Heien does not save the stop—definitions of sidewalk and roadway were not genuinely ambiguous, so mistake was not objectively reasonable
Attenuation (Brown/Strieff)	Even if initial stop unlawful, discovery of outstanding warrant attenuated the taint and justified search incident to arrest	Huez argued attenuation was not raised below and record is insufficient	Remanded for an evidentiary hearing on attenuation: appellate court found factors arguably cut both ways and the State failed to develop the record, so trial court must decide after additional evidence
Remedy and disposition	Suppress evidence and vacate conviction if attenuation not found	Affirm conviction if court finds attenuation and admits evidence	Remand for limited hearing on attenuation; if evidence admissible, affirm; if suppressed, vacate conviction

Terry v. Ohio, 392 U.S. 1 (1968) (reasonable‑suspicion standard for investigative stops; series of lawful acts can cumulatively create suspicion)
Brown v. Illinois, 422 U.S. 590 (1975) (three‑factor attenuation test for taint of illegal seizure)
Heien v. North Carolina, 574 U.S. 54 (2014) (reasonable suspicion may rest on an objectively reasonable mistake of law)
Utah v. Strieff, 136 S. Ct. 2056 (2016) (attenuation may apply where discovery of a preexisting warrant supplies independent justification)
State v. Hummons, 227 Ariz. 78 (App. 2011) (Arizona standards for suppression review and Brown attenuation application)
State v. Stoll, 239 Ariz. 292 (App. 2016) (discussing limits of Heien and objective reasonableness inquiry)