The police chased and caught him, patted him down and found an illegal weapon. Wardlow argued that the police had no constitutional basis to believe that he might be engaged in criminal activity. The trial court refused Wardlow's request, and the case ultimately reached the United States Supreme Court. Let's take a closer look at the law of search and seizure, and why this case makes an important contribution to it. The Fourth Amendment to the Constitution requires that to make a valid search, the police must first have probable cause to believe that contraband or other evidence of a crime will be uncovered.
Probable cause has no fixed definition.
In essence, it means that there is adequate objective information to form a belief that it is more likely than not that a crime has occurred or is occurring and that the suspect is involved. However, there are exceptions, such as when circumstances don't allow adequate time to get a warrant. In the Wardlow case, there was no search in the classic sense. As with probable cause, the definition varies from case to case. Reasonable suspicion requires less certainty than probable cause but more than a mere hunch.