Under what circumstances can an officer perform a search without a warrant?

An officer can perform a search without a warrant when probable cause is established. Probable cause means that there are reasonable grounds to believe that a crime has been committed or that evidence of a crime can be found in a specific location. This principle acknowledges that there are situations where waiting for a warrant may result in the loss of evidence or pose a danger to the officer or public safety.

In practice, probable cause can arise from an officer's observations, information from a reliable source, or evidence that appears in plain view, allowing the search to proceed without a warrant. This aligns with established legal precedents that balance the need for law enforcement to act quickly against the individual's right to privacy.

The other circumstances listed do not provide sufficient legal basis for a warrantless search. Cooperation, feelings of threat, or the nature of an offense do not in themselves justify omitting the requirement of a warrant, which is a critical protection against unreasonable searches and seizures.