What did Carroll v. US clarify about probable cause?

The case of Carroll v. US clarified that probable cause exists when the facts and circumstances within the officer's knowledge would lead a reasonable person to believe that a crime has been, is being, or will be committed. This definition emphasizes the importance of objective facts and evidentiary support rather than subjective feelings or opinions. Probable cause is a standard used to ensure that law enforcement actions, such as arrests or searches, are grounded in reasonable belief based on specific and articulable facts rather than mere intuition. Therefore, it reflects a balance between individual rights and the need for law enforcement to act effectively. This understanding is crucial for police officers to operate within the legal frameworks and protect citizen rights while pursuing criminal investigations.