"Probable cause is not equal to absolute certainty. That is, a police officer does not have to be absolutely certain that criminal activity is taking place to perform a search or make an arrest. Probable cause can exist even when there is some doubt as to the person's guilt."
In a Nutshell
"Probable cause" means reasonably reliable information to suspect there is a "fair probability" that a person has committed a crime, or that a search will reveal contraband or evidence. "Reasonable suspicion" is a strong suspicion, even if based on less information of a less-reliable nature, that a person is involved in criminal activity or may be armed and dangerous.