When does an arrest require probable cause?

• A. Sometimes
• B. Always
• C. Only with a warrant
• D. Never

Answer: (B)

Probable cause is the standard required to make any arrest. It means a reasonable belief, based on facts and circumstances known to the officer at the time, that a person has committed, is committing, or is about to commit a crime. This standard applies whether the arrest is made with a warrant or without a warrant. A warrant is issued only when probable cause is shown to a judge or magistrate, but warrantless arrests still require probable cause as the basis for the detention. If there’s no probable cause, the arrest is unlawful and any resulting evidence may be suppressed. So, an arrest requires probable cause in every case.