Are there exceptions to the exclusionary rule?
Yes. There are certain instances in which the Fourth Amendment is violated, yet the evidence can still be used against the criminal actor. The most notable is the Good Faith exception, which holds that evidence obtained by police officers who were relying in good faith on a valid search warrant that later is found to be lacking probable cause is still admissible. Under the Good Faith exception, evidence will be admissible when there is an objectively reasonable basis for the officers’ mistaken belief that the warrant authorized the search that they conducted. However, that exception does not apply if the police improperly execute the warrant; if the police provide false information to a judge to obtain the search warrant; if the search warrant is so deficient that a reasonable police officer couldn’t believe it to be valid; or if the police searched beyond the places covered in the search warrant.
It is important to note, however, that even if evidence is excluded because of a Fourth Amendment violation, that the evidence can still be used in several instances, including grand jury testimony, bail hearings, sentencing, and civil trials. Moreover, the exclusionary rule only applies to governmental actors (such as police officers); evidence obtained by private parties in violation of the Fourth Amendment can still be admitted in a criminal prosecution (as long as the private parties were not acting as an instrument of the government).