All evidence developed and obtained based on evidence obtained unconstitutionally is "fruit of the poisonous tree" and cannot be used at trial. Decided January 26, 1920 (argued December 12, 1919). Opinion of the Court: Holmes, joined by McKenna, Day, Van Devanter, McReynolds, Brandeis, Clark Dissenting: White, Pitney. Topic: Fourth Amendment rights. Silverthorne Lumber Co. v. United States, 251 U.S. 385 (1920), was a U.S. Supreme Court decision in which Silverthorne had attempted to evade paying taxes. Federal agents illegally seized tax books from Silverthorne and created copies of the records. The ruling, delivered by Oliver Wendell Holmes Jr., was that any evidence obtained, even indirectly, from an illegal search was inadmissible in court. He reasoned that otherwise, police would have an incentive to circumvent the Fourth Amendment to obtain derivatives of the illegally obtained evidence. This precedent later became known as the "fruit of the poisonous tree doctrine," and is an extension of the exclusionary rule. Wiki link