Final answer:
A search warrant, a legal document authorized by a judge based on probable cause, allows law enforcement officers to conduct searches and/or seizures. There are certain exceptions to the requirement of a warrant, including cases of consent, exigent circumstances, or lack of expectation of privacy.
Step-by-step explanation:
A search authorized by a search warrant must be made by law enforcement officers and is a process guided by the Fourth Amendment, which prohibits unreasonable searches and seizures and sets out requirements for search warrants. These warrants are legal documents, signed by a judge or magistrate, allowing police to perform searches and/or seizures. According to Amendment IV, a warrant can only be issued based on probable cause, supported by oath or affirmation, and must particularly describe the place to be searched and the persons or things to be seized.
However, there are exceptions to the warrant requirement, such as when a person lacks a "reasonable expectation of privacy," when an owner or renter consents to the search, or in exigent circumstances where evidence may be destroyed or in plain view. Furthermore, the courts have ruled that police do not need a warrant to search a car's passenger compartment or to search people at border entry points. It should be noted that while critics argue the requirement can be easily met by law enforcement, the process is based on probable cause, a legal standard that is a lower threshold than the proof required at a criminal trial.