Final answer:
Peace officers need to demonstrate probable cause that a crime has been committed or evidence will be found for a search. The Fourth Amendment protects against unreasonable searches and seizures by requiring a warrant supported by probable cause. However, exceptions allow for warrantless searches in certain circumstances like border searches or when there is a risk of evidence destruction.
Step-by-step explanation:
For a search, peace officers must articulate probable cause that a crime has been committed or that evidence will be found. Probable cause is the legal standard used to determine the constitutionality of a search or seizure. It is not as high as the standard of proof required for a criminal conviction but does require more than mere suspicion.
The Fourth Amendment of the U.S. Constitution states that "The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized." This requirement ensures that the government must show sufficient cause to a neutral judge or magistrate before conducting a search or seizure.
In some circumstances, such as during a border search or if there is imminent risk of evidence destruction, the requirement for a search warrant may be waived. Moreover, the Supreme Court has determined that there is a reduced expectation of privacy in certain situations, allowing for warrantless searches under specified conditions such as consent, evidence in plain view, or exigent circumstances.