Brown v. State, 439 P.3d 726

Corporal Gary Spears stopped Devon Brown for speeding and erratic driving; Brown said he was tired and returning from Torrington to Gillette and disclosed he was on unsupervised probation for marijuana possession.
Spears returned Brown’s identification without issuing a citation but, based on driving, probation status, a fleeting possible odor of marijuana, and Brown’s volunteered consent to a search (which Brown later revoked), sought to run a drug dog around the vehicle.
Brown hesitated, asked to call someone because the car belonged to his mother, then revoked consent; Spears deployed his K‑9, which alerted to the exterior, leading to a search that uncovered packaged marijuana.
Brown moved to suppress, arguing the canine sniff and continued detention after completion of the traffic stop violated the Fourth Amendment; the district court denied the motion.
Brown entered a conditional guilty plea preserving appeal of the suppression denial; the Wyoming Supreme Court reversed, concluding the post‑stop detention for the dog sniff was unsupported by reasonable suspicion.

Issue	Brown's Argument	State's Argument	Held
Whether the district court clearly erred in finding Brown’s demeanor changed when he revoked consent	Brown: bodycam shows polite, consistent behavior; no objectively suspicious demeanor change	State: hesitation and revocation reflected a demeanor change supporting suspicion	Court: finding of demeanor change clearly erroneous; revocation and request to call not suspicious behavior
Whether continued detention for canine sniff after traffic stop violated Fourth Amendment	Brown: stop concluded when ID was returned; remaining facts (probation, request to call) insufficient for reasonable suspicion	State: facts developed during stop (driving, probation, faint smell, demeanor) collectively supported reasonable suspicion	Court: excluding impermissible factors leaves only abrupt turn, inconsistent route, probation — insufficient for reasonable suspicion; detention unlawful
Whether Brown waived challenge to detention timing by conditional plea	Brown: preserved challenge to suppression broadly	State: argues waiver of some timing arguments	Court: no waiver — plea reserved right to appeal suppression order; court reviews full Fourth Amendment claim

Terry v. Ohio, 392 U.S. 1 (Terry stop standard for investigatory detention)
Rodriguez v. United States, 575 U.S. 348 (limits on extending traffic stops beyond completion of mission)
Dimino v. State, 2012 WY 131 (facts developed during initial stop may support further detention for canine sniff)
Sutton v. State, 2009 WY 148 (totality of circumstances analysis for reasonable suspicion)
Damato v. State, 2003 WY 13 (refusal to consent cannot form basis for reasonable suspicion)
United States v. Santos, 403 F.3d 1120 (10th Cir.) (prior criminal history insufficient alone but relevant with other factors)