I.
Thompson argues that because the airport search violated his fourth amendment rights, the district court erred in denying his motion to suppress evidence that he was carrying cocaine and a statement given by Thompson after his arrest. Thompson maintains that he was arrested when the officer took his airline ticket from him after being escorted back into the airport terminal, and that the police lacked probable cause to arrest him at this time. Thompson also claims the government did not establish that he consented to the search of his person and bag. He stresses that he was nineteen years old and was yelled at and told he was lying by the officers. Therefore, he maintains that any consent was not voluntary.
The magistrate determined that when Starbuck saw Thompson arrive at the time of day and from the city stated by the confidential informant, and that Thompson met every detail of the confidential informant’s description, Starbuck had personally verified all of the information given him by the informant, except whether Thompson had cocaine in his possession. Thus, Starbuck had reasonable grounds to believe that the remaining unverified bit of information — that the defendant possessed cocaine — was likewise true. Citing Draper v. United States, 358 U.S. 307, 313, 79 S.Ct. 329, 333, 3 L.Ed.2d 327 (1959), the magistrate held that Starbuck could have effected a lawful arrest as soon as he observed the defendant enter the terminal building.
In Draper, the Supreme Court stated that “probable cause exists where the facts and circumstances within [the arresting officer’s] knowledge and of which they had reasonable trustworthy information [are] sufficient in themselves to warrant a man of reasonable caution in the belief that an offense has or is being committed.” 358 U.S. at 313, 79 S.Ct. at 333 (citing Carroll v. United States, 267 U.S. 132, 162, 45 S.Ct. 280, 288, 69 L.Ed. 543 (1924)). We will uphold a finding of probable cause unless it is clearly erroneous. United States v. Henry, 763 F.2d 329, 331 (8th Cir.1985). In reviewing the record, we are satisfied that the magistrate’s factual findings are not clearly erroneous, and that he did not err in concluding from the totality of the circumstances that Starbuck had reasonable grounds to believe Thompson was in possession of drugs when he entered the airport terminal. The subsequent arrest of Thompson was therefore lawful.
As an alternative basis for denying Thompson’s motion to suppress evidence, the magistrate determined that Thompson voluntarily consented to the search of his bag and his person. The voluntariness of consent is a factual issue, and we will not overturn this and other findings of the magistrate, as adopted by the district court, unless clearly erroneous. See United States v. Campbell, 843 F.2d 1089, 1095 (8th Cir.1988); United States v. Turpin, 707 F.2d 332, 334 (8th Cir.1983).
Starbuck did not violate Thompson’s rights by approaching him, identifying himself, and asking him to answer questions. “Law enforcement officers do not violate the fourth amendment by merely approaching an individual on the street or in another public place by asking him if he is willing to answer some questions [and] by putting questions to him.” Campbell, 843 F.2d at 1092; see also Florida v. Royer, 460 U.S. 491, 497, 103 S.Ct. 1319, 1324, 75 L.Ed.2d 229 (1983).
Thompson contends, however, that when Starbuck took his ticket from him to examine it, this amounted to a seizure, which requires reasonable suspicion or probable cause. See INS v. Delgado, 466 U.S. 210, 215-17, 104 S.Ct. 1758, 1762-63, 80 L.Ed.2d 247 (1984). In determining whether a person has been seized, the inquiry is whether “a reasonable person would have believed that he was not free to leave.” United States v. Mendenhall, 446 U.S. 544, 554, 100 S.Ct. 1870, 1877, 64 L.Ed.2d 497 (1980). In this case, Starbuck took Thompson’s airline ticket from him during the initial encounter outside of the terminal and later inside the terminal. On both occasions, Starbuck immediately returned the ticket to Thompson after observing it and asking him questions concerning his identity. Starbuck had taken the ticket