PLEASE READ THIS BEFORE YOU COMMENT, EMAIL ME OR PHONE ME. I'm only licensed in CA. This answer doesn't make me your lawyer, and neither do follow-up comments and/or emails and/or phone calls --- we need an actual agreement confirmed in writing before any attorney-client relationship is formed. Please don't expect me to respond to your follow-up queries. This answer doesn't constitute legal advice, and shouldn't be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue.
In this situation I do not think it was a crime for the person to open the mail...it has to do with intent. What do you mean by "denounced" in this situation?
TITLE 18--CRIMES AND CRIMINAL PROCEDURE
CHAPTER 83--POSTAL SERVICE
Sec. 1702. Obstruction of correspondence
Whoever takes any letter, postal card, or package out of any post
office or any authorized depository for mail matter, or from any letter
or mail carrier, or which has been in any post office or authorized
depository, or in the custody of any letter or mail carrier, before it
has been delivered to the person to whom it was directed, with design to
obstruct the correspondence, or to pry into the business or secrets of
another, or opens, secretes, embezzles, or destroys the same, shall be
fined under this title or imprisoned not more than five years, or both.
(June 25, 1948, ch. 645, 62 Stat. 778; Pub. L. 103-322, title XXXIII,
Sec. 330016(1)(I), Sept. 13, 1994, 108 Stat. 2147.)
Disclaimer: This answer does not constitute legal advice. I am admitted in the States of New York, New Jersey and Massachusetts only and make no attempt to opine on matters of law that are not relevant to those three States. This advice is based on general principles of law that may or may not relate to your specific situation. Facts and laws change and these possible changes will affect the advice provided here. Consult an attorney in your locale before you act on any of this advice. You should not rely on this advice alone and nothing in these communications creates an attorney client relationship.