What must an officer have in order to conduct a search based on probable cause?

To conduct a search based on probable cause, an officer needs to demonstrate a reasonable belief specific to the crime involved. Probable cause requires that the officer has facts and circumstances within their knowledge that would lead a reasonable person to believe that a crime has been committed or that evidence of a crime is present in the location to be searched.

This concept is fundamental to ensuring that searches are conducted legally and constitutionally, protecting individuals' Fourth Amendment rights against unreasonable searches and seizures. Probable cause does not require absolute certainty or a high level of suspicion; rather, it is a standard based on the totality of the circumstances that gives rise to a belief that evidence may be found.

A clear admission of guilt from the suspect or evidence collected from a previous search may provide supportive information, but they do not independently satisfy the requirement for probable cause needed to justify a new search. Similarly, while a valid warrant signed by a judge does indicate that probable cause has been established, the question specifically asks for what the officer must have to act, which is the officer's own reasonable belief concerning the crime involved. The necessity for a warrant arises later in the process, contingent upon having established probable cause.