A detention is valid only where the circumstances known to the officer involve specific and articulable facts causing him to suspect that criminal activity has taken place or is about to occur and that the person he is about to detain is involved in that activity. Appellant was sitting in his car with the engine idling in the parking lot of a 7-Eleven. Because there had been a string of robberies at 7-Eleven stores in the past few days, the officer approached appellant. As he did so, the officer heard a “thud.” Appellant got out of his car and tried to avoid contact with the officer, but the officer told him to “hang on a second.” Based on the facts and the applicable standard, the Court of Appeal upheld the trial court’s ruling granting the motion to suppress. Nothing indicated that the officer matched appellant’s description to that of the robbers. And since the officer allowed appellant to get his identification from his car, this suggested he did not associate the noise he heard with danger.