United States v. Walton, 827 F.3d 682

On Aug. 29, 2012, Illinois State Trooper McVicker stopped a rented 2012 Chevrolet Suburban for minor traffic violations; vehicle had two occupants (driver Smoot, passenger Walton) and one bag.
McVicker learned the Suburban was rented at Denver airport for nearly $1,000, Smoot was not an authorized driver under the rental agreement, and Walton had a suspended license.
During the stop McVicker noted nervous behavior, inconsistent statements about a prior Kansas stop (whether the car had been searched and how long they were detained), and Walton’s criminal history (including a drug-trafficking offense) via dispatch.
After about 22–29 minutes (after preparing a written warning), McVicker asked Smoot and Walton for consent to search; Smoot consented to her bag, Walton refused a vehicle search; McVicker requested a canine unit.
A canine unit arrived ~22 minutes later; the dog alerted and a subsequent search uncovered >5 kg of cocaine concealed in a vehicle void. Walton moved to suppress; district court denied the motion and the Seventh Circuit affirmed.

Issue	Walton's Argument	Government's Argument	Held
Whether detention was unlawfully prolonged beyond the traffic-stop purpose	McVicker lacked reasonable suspicion by the time he completed the written warning, so further detention violated the Fourth Amendment	Totality of circumstances (large rental SUV, inconsistent stories, nervousness, Walton’s drug-related criminal history) gave reasonable suspicion to extend the stop	Court held there was reasonable suspicion and denial of suppression affirmed
Whether officer unreasonably delayed requesting canine unit (transforming stop into arrest)	Even if suspicion existed, McVicker unreasonably delayed requesting/obtaining the dog, making detention an arrest without probable cause	Officer acted diligently in questioning, seeking consent, then promptly requesting the canine; 22-minute canine response was not unreasonable	Court held officer acted diligently and the delay was reasonable

Rodriguez v. United States, 575 U.S. 348 (2015) (officer may not prolong traffic stop absent reasonable suspicion)
Arizona v. Johnson, 555 U.S. 323 (2009) (officer may ask unrelated questions during a stop if they do not measurably extend it)
United States v. Arvizu, 534 U.S. 266 (2002) (reasonable suspicion assessed under totality of the circumstances)
United States v. Sanford, 806 F.3d 954 (7th Cir. 2015) (criminal-history info from computer check can contribute to reasonable suspicion to wait for canine)
United States v. Martin, 422 F.3d 597 (7th Cir. 2005) (≈20-minute canine response time not an unreasonable delay)
United States v. Hill, 818 F.3d 289 (7th Cir. 2016) (use of totality-of-circumstances in reasonable-suspicion analysis)