Minn. Stat. § 609.4971: WARNING SUBJECT OF INVESTIGATION.

Whoever, having knowledge that a subpoena has been issued under sections 8.16 and 388.23, and with intent to obstruct, impede, or prevent the investigation for which the subpoena was issued, gives notice or attempts to give notice of the issuance of the subpoena or the production of the documents to a person, may be sentenced to imprisonment for not more than five years or to payment of a fine of not more than $10,000, or both.