Independent Source Rule Law and Legal Definition

Independent source rule is a legal principle stating that evidence obtained illegally should not be suppressed, if that evidence is later acquired from a constitutionally valid search or seizure. Independent source rule is an exception to the fruit of the poisonous doctrine. The fruit of the poisonous doctrine is a specific application of the exclusionary rule, when evidence is obtained as the result of illegal police conduct. The fruit of the tree doctrine also states that not only should that evidence be suppressed, but all evidence that is the "fruit" of that unlawful conduct should also be suppressed. [State v. McKinney, 361 N.C. 53 (N.C. 2006)]

For example, if information used to obtain a search warrant is obtained through an unconstitutional seizure, the warrant and the search conducted under it is considered illegal. However, under the independent-source rule, if the evidence obtained is independent of the unlawful police conduct which created probable cause to issue the warrant, then the warrant is valid.