What is "fruit of the poisonous tree"

n. (context US legal idiomatic English) evidence that has been obtained as the result of an illegal act on the part of law enforcement personnel (such as a warrantless search, or continued questioning of a witness who has invoked the right of counsel), and which is therefore excluded from being admitted as evidence in a trial.

n. a rule that once primary evidence is determined to have been illegally obtained any secondary evidence following from it may also not be used

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 (the "tree") of the evidence or evidence itself is tainted, then anything gained (the "fruit") from it is tainted as well. The fruit of the poisonous tree doctrine was first described in '' Silverthorne Lumber Co. v. United States'', 251 U.S. 385 (1920). The term's first use was by Justice Felix Frankfurter in Nardone v. United States (1939).

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 legal doctrine. The testimony of a witness who is discovered through illegal means would not necessarily be excluded, however, due to the “attenuation doctrine”, which allows certain evidence or testimony to be admitted in court if the link between the illegal police conduct and the resulting evidence or testimony is sufficiently attenuated. It is believed that a witness who freely and voluntarily testifies is enough of an independent intervening factor to sufficiently “attenuate” the connection between the government’s illegal discovery of the witness and the witness's voluntary testimony itself. (United States v. Ceccolini, 435 U.S. 268 (1978))

The "Fruit of the poisonous tree" 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:

1. it was discovered in part as a result of an independent, untainted source; or
2. it would inevitably have been discovered despite the tainted source; or
3. the chain of causation between the illegal action and the tainted evidence is too attenuated; or
4. the search warrant was not found to be valid based on probable cause, but was executed by government agents in good faith (called the good-faith exception).

This doctrine was also used by the European Court of Human Rights in Gäfgen v. Germany. In certain cases continental European countries have similar laws (e.g. in cases of torture), while the doctrine itself is generally not known. Illegally obtained evidence is used by the courts to ensure that the judgment is factually correct, however the person obtaining the illegal evidence typically faces independent consequences.

"Fruit of the Poisonous Tree" is the 11th episode of the American fairy tale/drama television series Once Upon a Time, which aired in the United States on ABC on January 29, 2012.

The series takes place in the fictional seaside town of Storybrooke, Maine, in which the residents are actually characters from various fairy tales that were transported to the "real world" town by a powerful curse. In this episode, Emma Swan ( Jennifer Morrison) is asked by Sidney ( Giancarlo Esposito) for help uncovering evidence that could expose Regina's ( Lana Parrilla) corrupt ways in Storybrooke, while in the Enchanted Forest, Snow White's ( Ginnifer Goodwin) father King Leopold ( Richard Schiff) is granted three wishes by a Genie (Esposito), which details the back story of the Magic Mirror's origins.

It was co-written by Andrew Chambliss and Ian B. Goldberg, while being directed by Bryan Spicer.