State v. Ribble, 1 CA-CR 16-0726

In August 2014 Officer Marchant stopped Ribble for failing to signal a right turn while he was following her in a police vehicle.
During the stop he observed repeated furtive movements by Ribble (leaning forward, shifting, moving her right arm behind her back) and inconsistent explanations about using a multi-tool/knife to start the car.
Officers removed Ribble and the passenger, requested consent to search (refused), then summoned a certified narcotics canine unit.
The dog alerted to the exterior of the driver’s door; a subsequent warrantless search located methamphetamine hidden in the driver’s seat.
Ribble moved to suppress the evidence, arguing the stop/prolongation lacked reasonable suspicion and the dog alert was unreliable; the superior court denied the motion.
A jury convicted Ribble of possession of dangerous drugs; the Court of Appeals affirmed the denial of the suppression motion.

Issue	Plaintiff's Argument (State)	Defendant's Argument (Ribble)	Held
Reasonable suspicion for initial traffic stop	Officer observed unsignaled turn while driving behind Ribble, satisfying A.R.S. § 28-754 and justifying the stop	The unsignaled turn did not affect other traffic, so no violation occurred	Stop was reasonable: officer in a police vehicle counts as "other traffic," so the stop was lawful
Reasonable suspicion to prolong stop for canine sniff	Officer observed furtive movements, inconsistent stories, visible multi-tool and fresh cut—collectively creating suspicion of concealed contraband	Movements and explanations were innocent and plausible; no articulable criminal suspicion to extend detention	Extension was justified: totality of circumstances produced reasonable, articulable suspicion to detain until canine arrived
Probable cause based on canine alert	Certified narcotics dog alerted to exterior of driver’s door; handler’s testimony supported reliability despite later minor illness	Dog was unreliable because it later showed respiratory symptoms and had difficulty in training the next day	Dog alert provided probable cause: court weighed handler testimony and circumstances and found the sniff sufficiently reliable for a warrantless search

United States v. Arvizu, 534 U.S. 266 (training and experience can make otherwise innocent acts suspicious)
Illinois v. Caballes, 543 U.S. 405 (traffic stop cannot be prolonged beyond mission without independent reasonable suspicion)
Florida v. Harris, 568 U.S. 237 (properly trained canine alert can establish probable cause evaluated by commonsense totality of circumstances)
State v. Teagle, 217 Ariz. 17 (deference to an officer’s interpretation of suspicious conduct)
State v. Salcido, 238 Ariz. 461 (an officer in a police vehicle qualifies as "other traffic" for signal/turn analysis)
State v. Sweeney, 224 Ariz. 107 (post-stop detention requires reasonable, articulable suspicion of criminal activity)