In reviewing a motion to suppress, what is the test for determining whether a probationer was detained without reasonable suspicion under the Fourth Amendment?

In reviewing a motion to suppress, we defer to the lower court's findings of fact supported by substantial evidence, but exercise independent judgment in determining whether the detention was reasonable under the Fourth Amendment. (People v. Glaser (1995) 11 Cal.4th 354, 362, 45 Cal.Rptr.2d 425, 902 P.2d 729.) In the trial court, the district attorney conceded that the initial stop was conducted without reasonable suspicion. Thus, the issue below turned on whether the defendant's status as a probationer rendered the validity of the initial stop irrelevant.