What is meant by the phrase "fruit of the poisonous tree?"
The phrase “fruit of the poisonous tree” is a legal phrase used in the United States to describe evidence gathered with the aid of information 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") would also be tainted.Such evidence is not generally admissible in court. For example, if a police officer conducted a search of a home in violation of the Fourth Amendment of the U. S. Constitution, and obtained a key to a locker in a train station, thus obtaining evidence of a crime, then that evidence would more than likely be excluded in accordance with the fruit of the poisonous tree doctrine. This legal 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.