Traffic stop prolonged for a dog sniff and an ex-felon registration check, which were unrelated to the traffic violation, violates the Fourth Amendment unless the officer had independent reasonable suspicion to prolong the detention. A Nevada officer stopped Evans for making an unsafe lane change and following a vehicle too closely. After questioning Evans and conducting a check for outstanding warrants, the officer requested an ex-felon registration check, which took eight minutes to process. Evans was properly registered. The officer issued Evans a warning and told him “you’re good to go.” Before Evans could leave, the officer asked him for consent to search his car. Evans refused. The officer conducted a dog sniff and the dog alerted. Officers searched the car and found drugs. Evans was charged with drug-related offenses. Before trial, he moved to suppress the drugs on the basis that his traffic stop had been unlawfully prolonged by the ex-felon check and the dog sniff. The district court agreed and suppressed the evidence. The government appealed. Held: Vacated and remanded. While the appeal was pending, the U.S. Supreme Court decided Rodriguez v. United States (2015) 135 S.Ct. 1609, which held that traffic stops violate the Fourth Amendment when they are prolonged beyond the time reasonably required to complete the tasks tied to the traffic infraction, unless the prolongation is supported by independent reasonable suspicion. Applying Rodriguez, the Ninth Circuit held that both the ex-felon registration check and dog sniff were unrelated to Evans’s traffic violation and prolonged the traffic beyond the time required to complete the mission of the traffic stop. However, the Ninth Circuit remanded the case back to the district court to consider in the first instance whether the ex-felon registration check and dog sniff were supported by independent reasonable suspicion.