What must consent to search be according to Fourth Amendment principles?

Consent to search, according to Fourth Amendment principles, must be voluntary and not a result of duress. This means that individuals should freely agree to the search without being pressured, threatened, or manipulated by law enforcement. The concept of voluntary consent is pivotal because the Fourth Amendment protects individuals from unreasonable searches and seizures, and consent that is coerced or given under pressure does not meet the constitutional requirement for validity.

Voluntary consent is assessed based on the totality of the circumstances, including the individual's understanding of their rights and the setting in which consent is given. Courts look for clear indicators that the person granting consent is doing so of their own free will.

Other options do not align with Fourth Amendment standards. Coerced consent would violate fundamental rights; implicit consent would not meet the legal threshold for clarity; and requiring explicit consent only in writing is not a requirement under the Fourth Amendment, as verbal consent can also be valid if it meets the criteria of voluntariness.