What is the test for reasonable suspicion under the Fourth Amendment?

involved in that activity. [Citations.] This reasonable suspicion requirement is measured by an objective standard, not by the particular officer's subjective state of mind at the time of the stop or detention." (People v. Conway (1994) 25 Cal.App.4th 385, 388.) "Accordingly, the circumstances known or apparent to the officer must be such as would cause a reasonable law enforcement officer in a like position, drawing when appropriate on his or her training and experience, to suspect that criminal activity has occurred, is occurring, or is about to occur and that the person to be stopped or detained is involved in the activity." (Id. at p. 389.) "The corollary to this rule is that an investigative stop or detention predicated on circumstances which, when viewed objectively, support a mere curiosity, rumor, or hunch is unlawful, even though the officer may be acting in good faith." (Ibid.)

"The touchstone of our analysis under the Fourth Amendment is always 'the reasonableness in all the circumstances of the particular governmental invasion of a citizen's personal security.'" (Pennsylvania v. Mimms (1977) 434 U.S. 106, 108-109.)