a case go all the way to the Supreme Court on this issue. A sketchy-looking guy came out of a drug house that was under surveillance. The cops stopped him and asked him for his ID. They then found out there were warrants for his arrest, they searched him, and found drugs.
The court found there was no reasonable suspicion, but the Supreme Court (Justice Thomas, I think) ultimately found the search to be lawful because of all of the circumstances surrounding what happened. I disagree with that decision, believing that no reasonable suspicion means the subsequent search was improper, but the court decided otherwise.