What is the test for reasonable-suspicion?

In making reasonable-suspicion determinations, reviewing courts "must look at the 'totality of the circumstances' of each case to see whether the detaining officer has a 'particularized and objective basis' for suspecting legal wrongdoing. [Citation.] This process allows officers to draw on their own experience and specialized training to make inferences from and deductions about the cumulative information available to them that 'might well elude an untrained person.' [Citations.]" (United States v. Arvizu (2002) 534 U.S. 266, 273 (Arvizu).) "Although an officer's reliance on a mere '"hunch"' is insufficient to justify a stop, [citation], the likelihood of criminal activity need not rise to the level required for probable cause, and it falls considerably short of satisfying a preponderance of the evidence standard [citation]." (Id. at p. 274.)