Fruit of the Poisonous Tree Law and Legal Definition

Fruit of the poisonous tree is a doctrine of evidence law first established in Silverthorne Lumber Co. v. U.S. (1920). According to this doctrine, not only is evidence illegally seized inadmissible, but any evidence or testimony obtained later as a result of the illegally seized evidence is inadmissible.

This has been somewhat weakened by the good faith exception, but it basically means that any secondary, incriminating facts or leads discovered later in a case from an earlier, illegal seizure are inadmissible. If the "tree" is tainted, the "fruits" are also tainted. One loophole is the purged taint exception, which applies if the defendant broke the chain of evidence themself, and came forward with new evidence, like a spontaneous confession, about a related crime.