Terry and found that they comported with the "reasonable suspicion" standard. McFadden had years of experience as a policeman and was able to articulate the observations that led him to suspect that Terry and the other men were preparing to rob the store. Since McFadden reasonably suspected that the men were preparing for armed robbery, he reasonably suspected that Terry was armed, and so his frisk of Terry's clothing was permissible and did not violate Terry's Fourth Amendment rights. The Court ended its opinion by framing the issue very narrowly, saying the question it was answering was "whether it is always unreasonable for a policeman to seize a person and subject him to a limited search for weapons unless there is probable cause for an arrest." In answer to this limited question, the Court said it was not. It ruled that when an American policeman observes "unusual conduct which leads him reasonably to conclude in light of his experience that criminal activity may be afoot and that the persons with whom he is dealing may be armed and presently dangerous", it is not a violation of the Fourth Amendment for the policeman to conduct a "stop-and-frisk" of the people he suspects. Concurring opinion of Justice White Justice White joined the opinion of the Court but suggested that There is nothing in the Constitution which prevents a policeman from addressing questions to anyone on the streets. Absent special circumstances, the person approached may not be detained or frisked but may refuse to cooperate and go on his way. However, given the proper circumstances, such as those in this case, it seems to me the person may be briefly detained against his will while pertinent questions are directed to him. Of course, the person stopped is not obliged to answer, answers may not be compelled, and refusal to answer furnishes no basis for an arrest, although it may alert the officer to the need for continued observation. With regard to the lack of obligation to respond when detained under circumstances of Terry, this opinion came to be regarded as persuasive authority in some jurisdictions, and the Court cited these remarks in dicta in Berkemer v. McCarty, , at 439. However, in Hiibel v. Sixth Judicial District Court of Nevada, , the Court held that neither of these remarks was controlling in a situation where a state law required a detained person to