The Court came up with a two part test in the Katz case: (1) Does the suspect have a subjective expectation of privacy, and (2) Does society recognize it as reasonable …

The Test – The Golden Rule: When asking whether you can do a search or seizure without a warrant, just ask, “Is it reasonable?” We’ll get to the exceptions over the next several months, but always, always, start with that analysis.

While there are several bright-line exceptions, each of those exceptions is an outgrowth of the basic principles of the Fourth Amendment. The Fourth Amendment simply prohibits police officers from conducting “unreasonable searches and seizures.”