Fruit of the poisonous tree is a legal metaphor in the United States used to describe evidence that is obtained illegally. The logic of the terminology is that if the source of the evidence (the "tree") is tainted, then anything gained from it (the "fruit") is tainted as well. The term fruit of the poisonous tree was first used in Nardone v. United States in the opinion by Justice Felix Frankfurter.
Such evidence is not generally admissible in court. For example, if a police officer conducted an unconstitutional (Fourth Amendment) search of a home and obtained a key to a train station locker, and evidence of a crime came from the locker, that evidence would most likely be excluded under the fruit of the poisonous tree doctrine. The discovery of a witness is not evidence in itself because the witness is attenuated by separate interviews, in-court testimony and his or her own statements.
The doctrine is an extension of the exclusionary rule, which, subject to some exceptions, prevents evidence obtained in violation of the Fourth Amendment from being admitted in a criminal trial. Like the exclusionary rule, the fruit of the poisonous tree doctrine is intended to deter police from using illegal means to obtain evidence.
The doctrine is subject to four main exceptions. The tainted evidence is admissible if:
- it was discovered in part as a result of an independent, untainted source; or
- it would inevitably have been discovered despite the tainted source; or
- the chain of causation between the illegal action and the tainted evidence is too attenuated; or
- the search warrant not based on probable cause was executed by government agents in good faith (called the good faith exception).
The fruit of the poisonous tree doctrine stems from the 1920 case of Silverthorne Lumber Co. v. United States.
Famous quotes containing the words fruit of, fruit, poisonous and/or tree:
“The natural historian is not a fisherman who prays for cloudy days and good luck merely; but as fishing has been styled “a contemplative man’s recreation,” introducing him profitably to woods and water, so the fruit of the naturalist’s observations is not in new genera or species, but in new contemplations still, and science is only a more contemplative man’s recreation.”
—Henry David Thoreau (1817–1862)
“As for America, it is the ideal fruit of all your youthful hopes and reforms. Everybody is fairly decent, respectable, domestic, bourgeois, middle-class, and tiresome. There is absolutely nothing to revile except that it’s a bore.”
—Henry Brooks Adams (1838–1918)
“The impression made on a wise man is that of universal innocence. Poison is not poisonous after all, nor are any wounds fatal. Compassion is a very untenable ground. It must be expeditious. Its pleadings will not bear to be stereotyped.”
—Henry David Thoreau (1817–1862)
“There is something singularly grand and impressive in the sound of a tree falling in a perfectly calm night like this, as if the agencies which overthrow it did not need to be excited, but worked with a subtle, deliberate, and conscious force, like a boa-constrictor, and more effectively then than even in a windy day.”
—Henry David Thoreau (1817–1862)