Fruit of the Poisonous Tree
Definition
A US doctrine extending the exclusionary rule: not only is unlawfully obtained evidence itself excluded, but any further evidence discovered as a result of that unlawful search is also excluded. The original unlawful act 'poisons' all evidence derived from it, unless an exception such as independent source or inevitable discovery applies.
- Jurisdiction
- United States
- Extends
- The exclusionary rule
- Covers
- Evidence derived from an unlawful search or seizure
- Exceptions
- Independent source, inevitable discovery
Common questions
What is the independent source exception to the fruit of the poisonous tree doctrine?+
If the same evidence was also obtained through a separate, lawful investigative path that did not depend on the initial illegality, prosecutors can rely on that untainted source instead, so the evidence is not automatically excluded just because an unlawful search also happened to lead to it.
Does this doctrine apply outside the United States in the same form?+
Not uniformly. Many jurisdictions, including the UK and India, apply a more discretionary balancing test to unlawfully derived evidence rather than the US's near-automatic exclusion, weighing factors like the seriousness of the breach against the evidence's reliability and probative value.
Related terms
- Chain of Custody
- The documented chronological record of who collected, handled, transferred, and examined a piece of evidence. For digital evidence, chain of custody includes...
- Exclusionary Rule
- A rule that evidence obtained in violation of constitutional or statutory search-and-seizure requirements cannot be used at trial. Applied strictly and automatically...
- Plain-View Doctrine
- A rule permitting an officer who is lawfully present in a location to seize evidence whose incriminating character is immediately apparent, without...
- Probable Cause / Reasonable Grounds
- The standard of suspicion required before a warrant may issue or a warrantless search may occur. In US law, probable cause requires...
- Search Warrant
- A judicial order authorising officers to enter and search a specified place and seize specified items. In most systems it must describe...