fruit of the poisonous tree
1: a doctrine of evidence: evidence that is derived from or gathered during an illegal action (as an unlawful search) cannot be admitted into court
2: evidence that is inadmissible under an evidentiary exclusionary rule because it was derived from or gathered during an illegal action see also wong sun v. u.s. in the important cases section compare independent source, inevitable discovery, plain view
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.