What is probable cause and when is it required?

• A. Reasonable belief that a person has committed a crime, required for arrests and for obtaining warrants.
• B. A mere hunch that someone may be guilty.
• C. The same as reasonable suspicion, used for stops.
• D. It is only needed for search warrants, not arrests.

Answer: (A)

Probable cause means a reasonable belief, based on facts and circumstances, that a crime has been committed and that the person involved is connected to it. It’s more than a hunch but not a guarantee; the belief must be grounded in reliable information and reasonable inferences drawn from the totality of the circumstances.

This standard is what authorizes two fundamental actions: arresting someone without a warrant and obtaining a warrant to arrest or search. For an arrest, officers must have probable cause at the moment of taking someone into custody. For a warrant, the judge or magistrate must be persuaded by facts and evidence presented that probable cause exists to believe a crime has been or is being committed and that the person named is involved.

It’s important to distinguish this from reasonable suspicion, which is a lower threshold used for stop-and-frisk or investigative detentions. A mere hunch or guess does not meet probable cause.