To be reasonable, all searches and seizures must be based upon probable cause.

• A. True
• B. Not necessarily
• C. It depends on the circumstances
• D. False

Answer: (D)

The Fourth Amendment’s reasonableness standard recognizes that not all searches and seizures must be based on probable cause. There are well-established exceptions that allow actions without it. For example, police can stop and briefly detain someone if they have reasonable suspicion of criminal activity, and they may frisk for weapons if they have reason to fear danger. Searches can also be conducted with voluntary consent, without any probable cause. Exigent circumstances—urgent situations where delay could put people at risk or lead to the destruction of evidence—permit warrantless searches as well. A lawful arrest permits a search incident to arrest, limited to the arrestee and the area within reach, without a separate warrant. These situations illustrate that reasonableness can be satisfied without probable cause, so the statement is false.