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The Exclusionary Rule  

What is the Exclusionary Rule?

When a defendant's Fourth, Fifth or Sixth Amendment rights have been violated, the exclusionary rule may apply. The exclusionary rule prevents evidence that was illegally obtained from admission at trial. The exclusionary rule was created by case law in 1914 and was made applicable to the states through case law in 1961. The exclusionary rule is a judicial mandate.

Elements of the Exclusionary Rule

There are three basic elements necessary in order for the exclusionary rule to apply. The first element is an illegal action by a police officer or agent of the police. The second element is that the evidence must be secured and seized. The third element is a causal connection between the illegal action and the evidence seized. The exclusionary rule is not applicable in civil proceedings, to grand juries, or to actions involving agency rules. Additionally, the search in question must violate the federal or state constitution or a federal or state statute in order for the exclusionary rule to be invoked.


Although the defendant's constitutional rights may have been violated if an illegal search and seizure occurred, evidence obtained through the illegal search and seizure still may be admissible. The exceptions are commonly referred to as exceptions to the "fruit of the poisonous tree doctrine." Those exceptions include:

  • Evidence is obtained from a source independent of the illegality. For example, two searches are conducted and produce the same evidence. One of the searches is illegal; the other is not. The evidence from the second search is admissible.
  • An intervening act of free will on behalf of the defendant has occurred
  • The evidence would have been inevitably discovered.
  • The good faith exception applies. This is when an officer receives a warrant and acts on it to seize evidence, but there was an error in the issuance of the warrant.


The defendant is entitled to have the applicability of the exclusionary rule decided outside of the presence of a jury. Typically, during the pretrial phase, the defendant will file a motion to suppress the evidence seized. The defendant may testify at his suppression hearing. However, anything that the defendant testifies to during his suppression hearing may not be used against him during his trial. If the evidence is excluded from the prosecution's case-in-chief, it still may be admissible during rebuttal when attempting to determine credibility of witnesses. The prosecution bears the burden of proving that the evidence is admissible. The prosecution must either establish that no violation of the defendant's constitutional rights occurred or that one of the exceptions was applicable.


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