United States v. Chow, 16-8115

Trooper Kirlin stopped Kwok Lun Chow for speeding while Chow drove a rented U-Haul; Chow was asked to sit in the patrol car while a warning was completed.
After the stop, Kirlin returned Chow's documents but asked additional questions; Chow initially volunteered more information and consented to Kirlin speaking with the passenger, Jia Jun Yu.
Chow and Yu gave materially inconsistent accounts about Chow's residence, employment, and relationship (cousin vs. friend); Chow displayed pronounced nervousness.
After questioning Yu, Kirlin told Chow he was detained and read Miranda warnings; Chow then admitted there was marijuana in the U-Haul. About 292 pounds of marijuana were seized.
Chow moved to suppress the evidence, arguing the detention after Yu's questioning lacked reasonable, articulable suspicion; the district court denied the motion.
Chow pleaded guilty conditionally, preserving appeal of the suppression ruling; he appealed only the reasonable-suspicion ruling (and raised but did not preserve an argument that the Miranda warning converted the detention into an arrest).

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether continued detention after passenger questioning was supported by reasonable, articulable suspicion	Chow: Facts (inconsistent statements, nervousness) were insufficient to justify detention	Gov't: Inconsistent accounts between Chow and passenger plus excessive nervousness provided reasonable suspicion	Held: Affirmed — totality of circumstances (inconsistent statements and excessive nervousness) gave reasonable suspicion to detain and extend stop
Whether giving Miranda warnings converted detention into an arrest requiring probable cause	Chow: Miranda warning amounted to an arrest unsupported by probable cause (raised on appeal)	Gov't: Not reached on merits; issue was not preserved below	Held: Not considered on appeal — claim not presented to district court and falls outside rights reserved by conditional plea

United States v. Arvizu, 534 U.S. 266 (discusses reasonable-suspicion standard under totality of the circumstances)
United States v. Mendez, 118 F.3d 1426 (10th Cir. 1997) (totality-of-circumstances test for detention)
United States v. Karam, 496 F.3d 1157 (10th Cir. 2007) (confusion and evasive answers can support reasonable suspicion)
United States v. Valles, 292 F.3d 678 (10th Cir. 2002) (assessing reasonable suspicion under totality of the circumstances)
Sokolow v. United States, 490 U.S. 1 (reasonable suspicion does not require probable cause; individual factors may be innocuous alone)
United States v. Kitchell, 653 F.3d 1206 (10th Cir. 2011) (passenger and motorist inconsistent statements can give rise to reasonable suspicion)
United States v. Santos, 403 F.3d 1120 (10th Cir. 2005) (unusual nervousness may factor into reasonable-suspicion analysis)
United States v. Price, 265 F.3d 1097 (10th Cir. 2001) (standard of review for suppression rulings)
United States v. Anderson, 374 F.3d 955 (10th Cir. 2004) (claims not raised in district court are outside the scope of appeals preserved by a conditional guilty plea)