MBE Fast Fact: Fruit of the Poisonous Tree

The "Fruit of the Poisonous Tree" doctrine makes it possible for the exclusionary rule to not only exclude evidence obtained in violation of the Fourth, Fifth, and Sixth Amendments, but also to exclude evidence obtained from exploitation of the unconstitutionally obtained evidence. To extend the symbolism, not only is the tree excluded (the evidence obtained in violation of the Amendments), but the fruit of that tree (evidence that would not have been obtained had the illegally obtained evidence not been obtained) is also excluded.

For MBE purposes, knowing when this doctrine does not apply is just as important as understanding the doctrine itself. The doctrine does not apply to evidence derived in violation of Miranda, evidence obtained from a source independent of the illegally obtained evidence, evidence obtained as a result of an intervening act of free will by the defendant, evidence that the police would have discovered regardless of the illegally obtained evidence (often deemed the "inevitable discovery doctrine,) and evidence obtained in violation of the “knock and announce rule.”