If you have never heard of the fruit of the poisonous tree doctrine, you may well wish to ask your criminal defense attorney about it when you find yourself facing criminal charges of any kind. It may turn out to play a huge role in the prosecution against you.
FindLaw explains that, confusingly enough, the fruit of the poisonous tree doctrine has absolutely nothing to do with either fruit or trees. Rather, the doctrine’s name is a metaphor for the proposition that the state cannot use any evidence, i.e., fruit, against you in court that it obtained in an illegal manner, i.e., a poisonous tree. In other words, the judge must throw out all such evidence.
Fourth Amendment underpinnings
The U.S. Supreme Court established the doctrine in the 1920 case of Silverthorne Lumber Co. v. United States, but Justice Frankfurter actually coined the phrase when he wrote the opinion for the 1939 case of Nardone v. United States.
The doctrine, and its companion exclusionary rule both stem from your constitutional right to remain free of unreasonable government searches and seizures. While no statute or court decision has ever defined exactly what constitutes an unreasonable search or seizure, judges always look with suspicion on those conducted without a valid warrant.
The fruit of the poisonous tree doctrine applies not only to the evidence the government obtains at the time it conducts an unreasonable search or seizure, but also to any additional evidence it obtains afterward that it would not have obtained had it not been for the original illegal search or seizure.