Reasonable suspicion is a standard used in criminal procedure. It is looser than probable cause. Reasonable suspicion is sufficient to justify brief stops and detentions, but not enough to justify a full search. When determining reasonable suspicion, courts consider the events leading up to the brief stop and a decide whether these facts, viewed from the standpoint of an objectively reasonable police officer, amount to reasonable suspicion.
Courts look at the totality of the circumstances of each case to see whether the officer has a particularized and objective basis for suspecting legal wrongdoing.