bag. By now, it was 9:30 p. m., too late for the agents to obtain a second warrant. They allowed respondent to leave for the night, but kept his luggage. The next morning, after a second dog confirmed Donker's alert, the agents obtained a warrant and found 1,063 grams of cocaine inside the bag.
Respondent was indicted for possession with the intent to distribute cocaine in violation of 21 U. S. C. § 841(a)(1). The United States District Court for Hawaii denied his motion to suppress the cocaine and other evidence seized from his luggage, finding that the DEA agents had a reasonable suspicion *6 that he was involved in drug trafficking when they stopped him at the airport. Respondent then entered a conditional plea of guilty to theoffense charged.
The United States Court of Appeals for the Ninth Circuit reversed respondent's conviction by a divided vote, holding that the DEA agents did not have a reasonable suspicion to justify the stop. 831 F. 2d, at 1423.[2] The majority divided the facts bearing on reasonable suspicion into two categories. In the first category, the majority placed facts describing "ongoing criminal activity," such as the use of an alias or evasive movement through an airport; the majority believed that at least one such factor was always needed to support a finding of reasonable suspicion. Id., at 1419. In the second category, it placed facts describing "personal characteristics" of drug couriers, such as the cash payment for tickets, a short trip to a major source city for drugs, nervousness,