United States v. Cornejo, 196 F. Supp. 3d 1137

On Dec. 13, 2014 Deputy Gunsauls stopped Jairo Cornejo’s rented Nissan on I-5 for a radar speed reading; Cornejo produced a Washington license and a handwritten Enterprise rental agreement.
Gunsauls ran checks (plate, warrants) and waited for backup (Deputy Hughes); about 12 minutes after the stop Gunsauls began filling out a one-page warning and asked multiple questions not strictly related to the traffic violation.
After ~20 minutes Gunsauls directed Hughes to finish the warning while he deployed a narcotics K-9; the dog alerted to the front of the vehicle, the deputies searched the car and discovered large quantities of methamphetamine and heroin and other items.
Cornejo was arrested; he moved to suppress the physical evidence seized and statements made after the traffic stop on Rodriguez v. United States grounds.
The court held (1) the deputies unreasonably prolonged the stop by asking unrelated questions and delaying completion of the warning ticket before performing the K-9 sniff, and (2) because the prolonged detention lacked independent reasonable suspicion, the K-9 sniff and ensuing search were unlawful.
The court suppressed the drugs, money, phones, rental agreement and GPS, and any statements made after the unlawful prolongation; it denied suppression as to statements made before the prolongation.

Issue	Plaintiff's Argument (Cornejo)	Defendant's Argument (Government)	Held
Whether deputies unlawfully prolonged the traffic stop under Rodriguez by engaging in unrelated questioning and performing a K-9 sniff that added time to the stop	The deputies extended the stop beyond the mission of the traffic stop by asking unrelated questions and delaying completion of the warning; the K-9 sniff therefore required independent reasonable suspicion	The additional questioning and K-9 sniff were de minimis or reasonably related to completing the traffic mission; prior precedent (e.g., Caballes) permitted a sniff during a stop	Held unlawful: deputies unreasonably prolonged the stop (≈8+ minutes of unrelated delay) so the K-9 sniff required and lacked independent reasonable suspicion; search invalidated
Whether the good-faith exception (reliance on pre-Rodriguez precedent) salvages the evidence	Suppression appropriate because the prolongation was deliberate and exclusion will deter fishing-expedition stops	The deputies reasonably relied on existing precedent (e.g., Caballes) and acted in objective good faith, so evidence should not be suppressed	Held not applicable: Caballes did not authorize prolonging a stop beyond its mission; no binding Ninth Circuit precedent authorized the deputies’ conduct, so exclusionary rule applies

Rodriguez v. United States, 135 S.Ct. 1609 (2015) (a dog sniff that adds time to a traffic stop requires independent reasonable suspicion)
Illinois v. Caballes, 543 U.S. 405 (2005) (dog sniff during a lawful, nonprolonged traffic stop does not violate the Fourth Amendment)
Davis v. United States, 564 U.S. 229 (2011) (good-faith exception to exclusionary rule for searches conducted in objectively reasonable reliance on binding precedent)
Florida v. Harris, 133 S.Ct. 1050 (2013) (K-9 alert can establish probable cause if dog is reliable)
United States v. Shetler, 665 F.3d 1150 (9th Cir. 2011) (exclusionary rule applies to both direct and derivative evidence obtained from unconstitutional searches)