Final answer:
The exclusionary rule's purpose is to prevent evidence obtained in violation of the Fourth Amendment from being used in court, following the principles of 'fruit of the poisonous tree' and with exceptions like 'good faith' and 'inevitable discovery'.
Step-by-step explanation:
The purpose of the exclusionary rule according to the U.S. Supreme Court is to ensure that evidence obtained in violation of the Fourth Amendment cannot be used in court. The exclusionary rule's purpose is to prevent evidence obtained in violation of the Fourth Amendment from being used in court, following the principles of 'fruit of the poisonous tree' and with exceptions like 'good faith' and 'inevitable discovery'.
This principle was established in the landmark cases Weeks v. United States and Mapp v. Ohio. It applies not only to evidence found during an illegal search or seizure but also to any subsequent evidence that arises from it, described by the doctrine known as the "fruit of the poisonous tree". However, there are exceptions to this rule, such as the "good faith" exception and the "inevitable discovery" doctrine.