At common law, illegally seized evidence was admissible on the theory that the nature of the seizure did not necessarily affect the probative value of the evidence. However, in 1914 the United States Supreme Court, in order to protect the fourth amendment's guarantee of freedom from unreasonable searches and seizures, adopted a rule excluding from federal courts evidence illegally seized by federal officials. In 1961, the scope of this rule was extended by Mapp v. Ohio, which held that all evidence obtained in violation of the fourth amendment is inadmissible in state courts. However, the Mapp doctrine applies only to "official lawlessness," not to unlawful private seizures. Since Burdeau v. McDowell, in which the Supreme Court held that the Constitution does not forbid the admission in evidence in a criminal trial of papers illegally seized by private persons, state and federal courts have refused to exclude evidence in criminal prosecutions unless there was some official involvement in the unlawful search and seizure. However, the Michigan Supreme Court has not been strictly insistent upon finding official involvement as a prerequisite for excluding evidence considered offensive. In a 1958 civil wrongful death action, the court held that a blood sample taken by a private nurse without the defendant's consent was inadmissible because the "taking" violated the right to privacy granted by a Michigan constitutional provision similar to the fourth amendment. Although the fourth amendment to the federal constitution is now applicable to the states through the due process clause of the fourteenth amendment, under Burdeau there is no constitutional violation unless a governmental agency is involved in the illegal search and seizure.
Michigan Law Review,
Evidence Illegally Seized by Private Persons Excluded From Criminal Prosecution--People v. McComb,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol64/iss1/8