"Reasonable suspicion can never be supported on the basis of personal factors alone. For example, a personís colour, age, hairstyle or manner of dress, or the fact that he is known to have a previous conviction for possession of an unlawful article, cannot be used alone or in combination with each other as the sole basis on which to search that person. Nor may it be found on the basis of stereo-typed images of certain persons or groups as being more likely to commit offences."