It is a firmly established rule in the federal courts, that evidence obtained by an illegal search and seizure, within the purview of the Fourth Amendment to the Constitution of the United States, is not admissible providing timely steps are taken for its exclusion or return. However, that rule is limited in its application to federal officers or agents, so that quite generally it may be said, that evidence obtained by private,mdividuals or municipal or state officers, acting as such, is admissible in federal courts, regardless of the manner in which it is obtained.
Marion A. Marquis,
Notes and Comments,
Admissibility in Federal Courts of Evidence Wrongfully Obtained by Persons Other Than Federal Officers or by Cooperation Between Such Persons and Federal Officers,
Wash. L. & Rev.
Available at: https://digitalcommons.law.uw.edu/wlr/vol3/iss4/3