In Ohio v. Robinette (1996) 519 U.S. 33, an officer stopped a driver for speeding. (Id. at pp. 35-36.) After the officer checked the driver's license and registration, the officer asked the driver to step out of the car, whereupon the officer issued the driver a verbal warning and returned his license. (Ibid.) The officer then asked the driver if he was carrying any illegal contraband, weapons, or anything of the sort in the car, to which the driver responded, "No." (Ibid.) The officer obtained the driver's consent to search the car and found a small amount of marijuana and MDMA in pill form. (Ibid.) The United States Supreme Court found that the questioning and consent to search the car following the termination of the traffic stop were valid, holding that the "Fourth Amendment did not require a lawfully seized defendant to be advised he is 'free to go' before his consent to search will be recognized as voluntary." (Id. at p. 35.) "The Fourth Amendment test for a valid consent to search is that the consent be voluntary and 'voluntariness is a question of fact to be determined from all the circumstances.'" (Id. at p. 40.) The conclusion that subsequent questioning on unrelated issues and a request for consent to search may be permissible is implicit in its holding that drivers need not be advised that they are free to go before their consent to search will be considered voluntary. (Ohio v. Robinette, supra, 519 U.S. at p. 35.) The Supreme Court rejected a per se rule adopted by the lower court that required officers to advise citizens stopped for traffic offenses that they are free to go prior to any attempt at a consensual interrogation. The court emphasized the fact-specific nature of the reasonableness inquiry and stated that it would be "unrealistic to require police officers to always inform detainees that they are free to go before a consent to search may be deemed voluntary." (Ibid.)