Excerpted from: Investigations and Police Practices: Warrantless Searches and Seizures, 45 Georgetown Law Journal Annual Review of Criminal Procedure 49 (2016) (396 Footnotes) (Full Document)
Under the Fourth Amendment, every search or seizure by a government agent must be reasonable. In general, searches and seizures are unreasonable and invalid unless based on probable cause and executed pursuant to a warrant. However, certain kinds of searches and seizures are valid as exceptions to the probable cause and warrant requirements, including investigatory stops, investigatory detentions of property, searches incident to valid arrests, seizures of items in plain view, searches and seizures justified by exigent circumstances, consensual searches, searches of vehicles, searches of containers, inventory searches, border searches, searches at sea, administrative searches, and searches in which the special needs of law enforcement make the probable cause and warrant requirements impracticable.
