Final answer:
The Supreme Court has established that while the Fourth Amendment protects from unreasonable searches, there are exceptions that allow warrantless searches, such as lack of reasonable expectation of privacy, consent, or exigent circumstances. The exclusionary rule prevents evidence obtained from illegal searches from being used in court.
Step-by-step explanation:
The question relates to circumstances under which the Supreme Court has ruled that police can conduct a search without a warrant.
Notably, the Supreme Court has held that while the Fourth Amendment protects against unreasonable searches and seizures, there are certain exceptions. Police can search and/or seize without a warrant if an individual lacks a reasonable expectation of privacy, if consent is given, in exigent circumstances where evidence might be destroyed.
Warrantless searches have been addressed in multiple Supreme Court cases such as United States v. Jones and Carpenter v. United States, which extended protections against illegal search and seizure to include warrantless location tracking.
However, scenarios such as searching a car's passenger compartment, searches at international borders, and urgent situations with probable cause are exceptions to the warrant requirement. The exclusionary rule, established in Mapp v. Ohio, prevents the use of evidence obtained through illegal searches in courts.
Cases like Riley v. California reaffirmed the necessity of a warrant to search digital information on a seized cell phone, and Georgia v. Randolph emphasized that police cannot conduct a warrantless search in a home if one occupant objects, even if another consents.