Which type of search occurs without a warrant or probable cause?

The type of search that occurs without a warrant or probable cause is best described as a consent search. In the context of law enforcement, a consent search happens when an individual voluntarily agrees to allow officers to conduct a search without the need for a warrant or probable cause. The key element here is the individual's consent, which waives their Fourth Amendment rights against unreasonable searches and seizures.

It is essential to note that for a consent search to be valid, the consent must be given freely and voluntarily, not coerced or obtained under duress. This type of search empowers officers to gather evidence and pursue investigations while respecting the legal boundaries established by the Constitution, provided that the individual has the legal authority to grant consent.

In contrast, the other options presented involve different circumstances under which searches can occur. Emergency searches often arise when there are immediate concerns for safety or the destruction of evidence, while exigent circumstances searches apply when evidence could be lost or destroyed without immediate action. Investigative searches are typically broader and may require some level of suspicion or probable cause, distinguishing them from a consent search where a clear agreement to search is made.