United States v. Frazier, 30 F.4th 1165

Trooper Gibbs stopped Frazier on I-15 for speeding and lane-signal violations on Nov. 12, 2019; Gibbs saw a duffle bag in the back and an air‑freshener in the console.
During a roadside encounter Frazier fumbled to find the rental agreement, answered routine questions while looking at his phone, and produced two state IDs; Gibbs did not smell deodorizer or contraband.
Instead of promptly completing citation tasks, Gibbs paused to contact a K‑9 deputy to perform a dog sniff, later ran a DEASIL (DEA license‑plate reader) search, and called the rental company.
Deputy Peterson’s dog alerted; pat‑downs revealed a knife and then a pistol; a vehicle search uncovered fentanyl pills and ~1 kg cocaine.
District court denied Frazier’s motion to suppress; after a conditional guilty plea, Frazier appealed.
The Tenth Circuit reversed, holding the stop was impermissibly prolonged and the ensuing evidence inadmissible.

Issue	Frazier's Argument	Government's Argument	Held
Whether arranging a dog sniff prolonged the traffic stop in violation of Rodriguez and required independent reasonable suspicion	Gibbs impermissibly diverted from traffic mission to arrange a dog sniff without reasonable suspicion, so the stop was unlawfully prolonged	Gibbs had reasonable suspicion based on the duffle bag, partial window, air freshener, evasive answers, two IDs, missing rental agreement, rental/cross‑country travel	Held: The dog‑sniff detour prolonged the stop and Gibbs lacked reasonable suspicion at that point; the detour violated Rodriguez and was unlawful
Whether the DEASIL database query (and its results) cures the earlier violation or itself complied with Rodriguez	The DEASIL search occurred after the unlawful extension and cannot cure it; alternatively, DEASIL itself was an unlawful investigative detour	DEASIL provided independent reasonable suspicion and did not add time to the stop because it occurred while officers were otherwise waiting	Held: DEASIL could not retroactively cure the earlier violation; the DEASIL query itself exceeded the traffic mission and likely added time, and the government failed to prove otherwise; evidence is tainted and suppressed

Rodriguez v. United States, 575 U.S. 348 (2015) (officer may not prolong traffic stop for unrelated investigation absent reasonable suspicion)
Illinois v. Caballes, 543 U.S. 405 (2005) (use of a dog during a lawful traffic stop does not violate Fourth Amendment so long as it does not prolong the stop)
Wong Sun v. United States, 371 U.S. 471 (1963) (exclusionary rule: evidence obtained by exploitation of illegality is inadmissible)
United States v. Green, 897 F.3d 173 (3d Cir. 2018) (identify the "Rodriguez moment" and exclude later facts learned after an unlawful extension)
United States v. Gurule, 935 F.3d 878 (10th Cir. 2019) (contrast where traffic‑based tasks, not investigative detours, prolonged a stop)
United States v. Mayville, 955 F.3d 825 (10th Cir. 2020) (standard of review for suppression denials)
United States v. Cortez, 965 F.3d 827 (10th Cir. 2020) (reasonable‑suspicion standard under the Fourth Amendment)
United States v. Santos, 403 F.3d 1120 (10th Cir. 2005) (caution against giving weight to facts that are innocuously associated with travel)
United States v. Williams, 271 F.3d 1262 (10th Cir. 2001) (limitations on using inability to produce rental agreement to justify detention beyond traffic mission)
United States v. Davis, 636 F.3d 1281 (10th Cir. 2011) (rental status can be suspicious when paired with other objective indicia of deception)