Final answer:
Police can create an exigent circumstance justifying warrantless entry if there's an immediate need to act to prevent harm, escape, or destruction of evidence. Exceptions to the search warrant requirement include the good faith exception and the inevitable discovery doctrine. Illegally obtained evidence is excluded from court proceedings by the exclusionary rule and the fruit of the poisonous tree doctrine.
Step-by-step explanation:
Police can sometimes create an exigent circumstance justifying warrantless entry in the absence of prior exigencies, which typically requires either a warrant or consent. This scenario can occur when officers have a reasonable belief that waiting for a warrant would endanger life, facilitate escape, or lead to the destruction of evidence. For instance, police may hear screams from inside a residence or observe someone inside destroying what appears to be evidence. Such events could create an immediate need for police action that justifies a warrantless entry.
Additionally, exceptions to the warrant requirement, such as the good faith exception or inevitable discovery, may apply retrospectively if the search which was initially without a warrant is contested later in court. It is also critical to remember the plain view doctrine, where officers can legally seize items without a warrant if they observe them in plain view while legally present in an area.
However, any evidence obtained through an illegal search or seizure that does not meet an established exception is typically subject to the exclusionary rule. This principle, established by Mapp v. Ohio, prevents the use of evidence acquired illegally from being used in court. The related concept of fruit of the poisonous tree further extends this exclusion to any evidence subsequently obtained as a direct result of the illegal search.