In Knowles v. Iowa, 525 U.S. 113 (1998), an Iowa police officer stopped a driver for speeding and issued a citation rather than arresting the driver; the officer then searched the car, found marihuana, and arrested the driver. The United States Supreme Court held that the officer did not have reason to search the car. Id. Iowa courts had denied Knowles's motion to suppress, citing an Iowa statute permitting a search incident to the issuance of a citation for a traffic violation. Id. at 115. The Supreme Court concluded that a search incident to arrest is permissible on two bases: (1) the need to disarm the suspect in order to take him into custody; (2) the need to preserve evidence for later use at trial. Id. at 117. The Supreme Court found that neither basis was present in the search of Knowles's car. Id. at 117-18. Regarding the need to preserve evidence, the Court wrote: Once Knowles was stopped for speeding and issued a citation, all the evidence necessary to prosecute that offense had been obtained. No further evidence of excessive speed was going to be found either on the person of the offender or in the passenger compartment of the car. Iowa nevertheless argues that a "search incident to citation" is justified because a suspect who is subject to a routine traffic stop may attempt to hide or destroy evidence related to his identity (e.g., a driver's license or vehicle registration), or destroy evidence of another, as yet undetected crime. As for the destruction of evidence relating to identity, if a police officer is not satisfied with the identification furnished by the driver, this may be a basis for arresting him rather than merely issuing a citation. As for destroying evidence of other crimes, the possibility that an officer would stumble onto evidence wholly unrelated to the speeding offense seems remote. Id. at 118. The Court reversed the conviction and remanded the cause. The United States Supreme Court announced that warrantless searches incident to the issuance of a citation violated the Fourth Amendment. In so holding, the Court reasoned that where a citation is issued, unlike when an arrest is effectuated, the two historic rationales for a search incident to an arrest, i.e., the need to disarm defendant and the need to collect evidence, do not per se exist. Knowles, 525 U.S. at 116-18. The Court held that this was true even if the officers issuing the citation had probable cause to arrest the defendant. Id. The trial court concluded the following concerning the search of defendant's vehicle: The search of the defendant's vehicle on the night of December 1, 1998, although conceivably being a search incident to arrest, does not fall within the exception set out by the United States Supreme Court in United States v. Robinson, 414 U.S. 218 (1973), since there was no need to disarm the defendant in order to take him into custody and there was no need to preserve any evidence for later use at a trial, and further, that there was no indication on the part of the arresting officers at the time of the stop that the defendant had violated any of the criminal laws of this state other than driving while his license was revoked, and there was no other indication that the defendant was committing any other illegal act which would require a full "field search" of his vehicle, and the search later carried out was done without consent of the defendant and without probable cause. The United States Supreme Court declined to expand the search incident to arrest exception to the Fourth Amendment prohibition against warrantless searches. Unless either of the two historical rationales for the exception arise in a specific situation, i.e., ": (1) the need to disarm the suspect in order to take him into custody, and; (2) the need to preserve evidence for later use at trial," id. at 116, the Court held there is no search incident to citation exception. Id. at 488. In Knowles, the United States Supreme Court reversed a conviction based upon evidence seized during a traffic stop. The state defended the search as a reasonable "search incident to a summons," equating it to a search incident to arrest. The Supreme Court held that a non-custodial arrest, wherein the accused is released on a summons, does not justify an incidental search as an exception to the Fourth Amendment warrant requirement. See Knowles, 525 U.S. at 118-19. In sum, an officer who stopped the defendant for speeding ultimately discovered marijuana and related paraphernalia after a full search of defendant's vehicle. On appeal of the Iowa courts' refusal to suppress the drug evidence, the United States Supreme Court reversed and held that, where a police officer stops an individual for a traffic violation and issues only a citation, the officer may not conduct a full search of the individual's person or vehicle. In its analysis the supreme court also focused on the fact that once a traffic citation is issued, there exists no need for a further search for evidence in support of that offense.