What requirement does the Fourth Amendment place on law enforcement before making an arrest?

The Fourth Amendment of the United States Constitution protects individuals from unreasonable searches and seizures. When it comes to making an arrest, law enforcement is required to establish probable cause beforehand. Probable cause means that the officers must have enough factual evidence or reasonable grounds to believe that a person has committed a crime. This requirement serves as a safeguard against arbitrary arrests and ensures that individuals cannot be detained without sufficient justification.

Additionally, in certain situations, law enforcement may also need a valid search warrant, particularly if they intend to conduct a search of a property or a person during the arrest that exceeds the scope of the immediate search for weapons or evidence related to the arrest itself. However, having a warrant is not always necessary for an arrest; probable cause alone may suffice in many circumstances, especially in public settings where an officer directly observes a crime being committed.

Therefore, the correct answer indicates that law enforcement must establish probable cause, and it acknowledges that in certain cases, having a warrant can complement the process, making both elements important in the context of law enforcement actions.