What is the test for detention under the Fourth Amendment?

As to the first element, a detention does not comply with the Fourth Amendment unless the officers were 'aware of specific articulable facts, together with rational inferences from those facts, that reasonably warrant suspicion' that the individual was engaged in criminal activity. United States v. Brignoni-Ponse, 422 U.S. 873, 874 (95 S.Ct. 2574, 2577, 45 L.Ed.2d 607) ... (1975) .... The second factor in evaluating the reasonableness of a detention is the degree of intrusion into the individual's freedom. The greater the intrusion, the stronger the basis for the officers' action must be. In Dunaway v. New York, 442 U.S. 200, 99 S.Ct. 2248, 60 L.Ed.2d 824 (1979), for example, the police took a suspect from his home to the police station and kept him there for questioning. While the suspect was not technically under arrest, neither was he free to leave. The court held this detention too intrusive to be justifiable on the basis of mere reasonable suspicion. The suspect's liberty was sufficiently curtailed that, in order to be reasonable under the Fourth Amendment, probable cause was required. Id. at 216, 99 S.Ct. at 2258 .... In general, if probable cause is lacking, the intrusion must be no greater than the circumstances require." 638 F.2d at 520.