Also known as: independent sources · independent source doctrine · independent source rule
Written by attorneys · grounded in primary & secondary sources — see below
An exception to the exclusionary rule that permits the admission of evidence obtained through a source unconnected to prior unconstitutional conduct. The prosecution must demonstrate that the evidence was acquired by means wholly independent of the illegality. Courts apply the doctrine to both physical evidence and identification testimony after assessing whether the lawful source supplied the information without exploitation of the violation.
Select any source to read its text and confirm it supports the definition.
Officers illegally entered Isabelle Inman's warehouse and observed burlap-wrapped parcels containing marijuana. They later obtained a valid warrant based solely on an anonymous tip received before the entry and seized the parcels under that warrant. The court admitted the evidence because the warrant rested on information entirely separate from the unlawful entry.
Ines Ibarra glimpsed the robber for several seconds under bright lights during a bank holdup and later described the suspect accurately to police. After an unconstitutional single-photo display, she identified Ivan Ivanov in court. The court allowed the in-court identification after weighing her opportunity to view the robber, degree of attention, description accuracy, certainty, and short time interval since the crime.
Police learned the location of a victim's body through an illegal interrogation of Ismael Ibrahim. Search parties operating on independent leads were already closing in on the same area when officers lawfully discovered the remains hours later. The court admitted evidence of the body's location and condition because the discovery occurred through a source independent of the violation.
India Inoue challenged a state law restricting contraceptive access as violating a claimed right to marital privacy. The court examined whether the asserted interest arose from an independent source such as existing state law or longstanding understandings rather than from the Constitution itself. Finding no such independent source created a protected property or liberty interest, the claim failed.
Isaiah Ishikawa observed the perpetrator during a lengthy armed robbery under good lighting and provided a detailed description to police. After an unconstitutional post-indictment lineup conducted without counsel, he identified the defendant in court. The court admitted the in-court identification after finding it rested on the witness's original observation rather than the tainted lineup.
Integrity Partners offered expert statistical analysis linking a product to birth defects in a products-liability trial. The data underlying the opinion came from publicly available epidemiological studies obtained before any alleged discovery violation. The court admitted the testimony because the expert's conclusions rested on an independent source untainted by the procedural issue.
The prosecution must show that the evidence was obtained through a source wholly unconnected to the prior illegality. This requires demonstrating that police possessed probable cause for a warrant independent of the unlawful conduct and that they actually secured and executed such a warrant. Courts examine whether the information supporting the warrant came from a separate line of investigation.
A witness may give an in-court identification if it rests on an independent source untainted by an unconstitutional pretrial procedure. Courts weigh five factors: the witness's opportunity to view the perpetrator, degree of attention, accuracy of the prior description, level of certainty at the confrontation, and time between the crime and the identification.
…Ninth Amendment is applied against the States by the Fourteenth. Nor do I mean to state that the Ninth Amendment constitutes an independent source of rights protected from infringement by either the States or the Federal Government. Rather, the Ninth Amendment shows a belief of the Constitution's authors that fundamental rights exist…
…unlikely that 50 people who have nothing in common except that they ate at the same restaurant would get food poisoning from independent sources
…of counsel. I cannot agree, however, that the in-court identification must be excluded unless the Government can establish an independent source. The witnesses had an adequate opportunity to observe the robber at the time of the crime. Their identification at trial had an
…the information ultimately or inevitably would have been discovered by lawful means. The doctrine is an extrapolation from the independent source doctrine
…that that scheme would, absent some other provision of law, preclude Hamdan’s invocation of the Convention’s provisions as an independent source
Independent source requires proof that police actually obtained the evidence through a lawful means separate from the illegality. Inevitable discovery requires only a showing that the evidence would have been found by lawful means regardless of the violation. Both doctrines prevent automatic exclusion but rest on distinct factual showings.
No. A later warrant purges the taint only when it rests on information wholly independent of the illegality. If the warrant affidavit relies on facts learned during the unlawful search, the evidence seized under the warrant remains fruit of the poisonous tree and is inadmissible absent another exception.