Which of the following statements is true regarding arrests and the Fourth Amendment?

• A. An arrest can be based on reasonable suspicion
• B. An arrest requires probable cause
• C. An arrest requires a warrant in all cases
• D. An arrest requires consent

Answer: (B)

Arrests under the Fourth Amendment must be supported by probable cause—the facts and circumstances known to the officer must be enough to lead a reasonable person to believe the suspect committed a crime. This standard is higher than reasonable suspicion, which justifies only brief stops or investigative detentions, not full arrests. A warrant is not mandatory for every arrest; officers may effect a custodial arrest without a warrant when there is probable cause, especially in public places or when exigent circumstances exist. Consent is not the general requirement for an arrest; it may be relevant in other contexts like searches, but an arrest can be lawful without consent if probable cause is present. So the true rule is that an arrest requires probable cause.