Definition and Principle
The "Fruit of the Poisonous Tree" doctrine establishes that once a primary source of evidence ("the tree") is demonstrated to have been acquired unlawfully, any subsequent or derivative evidence ("the fruit") originating from it is also inadmissible. The underlying principle is that evidence illegally obtained by the State should not be utilized to procure other evidence, as the initial illegal act corrupts all evidence subsequently acquired. Illegally seized evidence is a direct consequence of the illegal act, while the "fruit of the poisonous tree" is an indirect result, at least one step removed from the original illegally seized evidence, but it is equally inadmissible.
Effect of Application
If evidence is procured through an unlawful search, the seized item is inadmissible against the accused. Generally, any evidence obtained in violation of constitutional rights, such as those related to search and seizure, is inadmissible for any purpose in any proceeding.
Distinction Between Primary Source and Derivative Evidence
Under this doctrine, a distinction exists between the primary source, referred to as "the tree," which is unlawfully obtained, and the secondary or derivative evidence, known as "the fruit," which is derived from the primary source. While the illegally seized evidence is the direct result of the illegal act, the "fruit of the poisonous tree" is an indirect outcome. Both the primary source and the derivative evidence are rendered inadmissible.
Contextual Mention
The concept has been referenced in situations involving the voluntariness or admissibility of a confession, suggesting that a retracted confession could be considered a "fruit of [a] poisonous tree" if its execution was involuntary or inadmissible. The doctrine is listed as a key concept in the subject of Evidence and as a topic under Remedial Law.