A California highway patrol officer stopped the pickup truck occupied by Lorenzo and Jose Navarette because it matched the description of a vehicle that an anonymous 911 caller had recently reported as having run her off the road. As he and the second officer approached the truck, they smelled marijuana. They searched the truck's bed, found 30 pounds of marijuana. And arrested both Navarettes. The Navarettes moved to suppress the evidence, arguing that the anonymous call to 911 did not give rise to a reasonable suspicion on the part of the officers and that the traffic stop therefore violated the Fourth Amendment. They further argued that if the traffic stop violated the fourth amendment, the evidence obtained in the search should be excluded under the fruit-of the poisonous-tree doctrine. The Navarettes' motion was denied. They were later convicted of drug-possession offenses. On appeal, the Navarettes reiterated their objection to the traffic stop and their objection to the use of the evidence obtained in the search. Did the traffic stop violate the Fourth Amendment? Should the evidence obtained in the ensuing search have been suppressed?